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What Exactly is an Eye Chart?

If there’s one aspect of optometry that everyone recognizes, it’s the traditional eye chart, with its rows of big letters on top, which gradually become smaller the farther down you go. This chart is usually known as the Snellen chart.

Yet how much do you really know about this eye chart? Are all eye charts the same? How are these eye charts used? And when were they invented?

Here’s everything you need to know about eye charts and more!

What is an Eye Chart?

An eye chart is one of the tools your eye doctor uses to assess your eyesight. Based on how well you can see various letters on the chart, your optometrist will determine whether you have myopia (nearsightedness), hyperopia (farsightedness), presbyopia (age-related farsightedness) or astigmatism, and will measure the prescription that will give you the clearest, most comfortable vision.

Are All Eye Charts The Same?

There are a number of variations to the standard Snellen eye chart. The one an eye doctor uses depends on the personal needs and abilities of the patient. For example, eye doctors will use charts with pictures or patterns for younger children who may not have learned to read or identify letters and numbers.

There are also certain charts that specifically measure distance vision, while others are better for measuring near vision.

History of the Snellen Eye Chart

The Snellen eye chart was developed by Dutch eye doctor Hermann Snellen in the 1860s. Before this standardized eye chart was developed, each eye doctor had their own chart that they preferred to use.

Having so many different eye charts made it impossible to standardize the vision correction available to patients. Eyeglass makers didn’t receive the defined measurements they needed to accurately design, manufacture and measure the optical prescriptions their patients needed.

For the first time, the Snellen eye chart allowed a person to provide a standardized prescription from any eye care provider they chose to any eyeglass maker, and get the same optical lenses to accurately correct their vision.

How The Snellen Chart Is Used in Eye Exams

The standard Snellen chart displays 11 rows of capital letters, with the first row consisting of a single large letter. The farther down the chart you go, the smaller the letters become.

Your eye doctor will ask you to look through a phoropter – an instrument used to test individual lenses on each eye during an eye exam – and look at the Snellen chart placed 20 feet away. Your eye doctor will prescribe the lenses that provide you with the clearest and most comfortable vision.

In many offices, where 20 feet of space may not be available, you’ll be asked to view the chart through a mirror. This provides the same visual experience as if you were standing 20 feet away.

If you have 20/20 vision, it means you can see what an average person can see on an eye chart from a distance of 20 feet. On the other hand, if you have 20/40 vision, it means you can only see clearly from 20 feet away what a person with perfect vision can see clearly from 40 feet away.

If you have 20/200 vision, the legal definition of blindness, this means what a person with perfect vision can see from 200 feet away, you can see from 20 feet away.

Does 20/20 Visual Acuity Mean Perfect Vision?

No. While eye chart tests identify refractive errors, they can’t detect signs of visual skill deficiencies or diseases such as glaucoma, cataracts or macular degeneration. These are diagnosed using advanced equipment as part of a comprehensive eye exam with your local eye doctor. Early diagnosis and treatment of eye conditions are essential to ensuring long-term vision and eye health.

For more information, give us a call at or visit us in person at , today!

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How do you keep your eyes healthy?

You only have one set of eyes – don’t take them for granted!

Make sure to implement the following habits for healthy eyes (and body). These include:

  • Eating a balanced diet rich in fiber, fruits and vegetables
  • Drinking plenty of water to hydrate your body and eyes
  • Not smoking, and avoiding 2nd-hand smoke
  • Wearing sunglasses to protect your eyes from ultraviolet (UV) rays
  • Maintaining normal BMI with regular exercise
  • Regular visits to your eye doctor as recommended

What health conditions can an eye exam detect?

A comprehensive eye exam can often detect certain underlying diseases that can threaten your sight and eye health, such as diabetes, high blood pressure, high cholesterol, tumors, autoimmune conditions and thyroid disorders. This is why having your eyes checked regularly is key. The earlier the diagnosis and treatment, the better the outcome and the higher your quality of life.

Bloodshot Eyes – Should You Be Concerned?

You wake up in the morning ready to start your day, only to discover that your eyes are bloodshot. That might not be surprising if you stayed up late to finish a project, had too many drinks at a party or spent time in a smoke-filled room.

But bloodshot eyes can also signal an underlying eye problem. If your eyes appear red or bloodshot, make an appointment with an eye doctor for a comprehensive eye exam to determine the cause and to receive effective treatment.

Why Do I Have Bloodshot Eyes?

When blood rushes to the front of the eye, the tiny red blood vessels on the white of the eye dilate and become visible. This makes the eyes appear red and irritated.

So why do these blood vessels dilate, causing your eyes to look bloodshot?

Bloodshot eyes tend to be caused by:

  • Dry eyes
  • Irritants such as smoke, pollen and perfume
  • Lack of sleep
  • Excessive alcohol consumption
  • Spending too much time in front of the computer

Bloodshot eyes due to lifestyle and environmental irritants may disappear on their own, or you can try to relieve them with over-the-counter eye drops or liquid tears. Lifestyle changes, such as getting more sleep, cutting down on alcohol intake and limiting screen time can often be helpful. If allergies are the culprit, oral antihistamines and antihistamine eye drops may relieve symptoms.

At other times, underlying problems requiring prompt medical attention can cause your eye’s blood vessels to dilate. The following are some of these medical conditions:

Conjunctivitis

You’ve probably heard of “pink eye.” It’s another name for infectious conjunctivitis – an infection of the conjunctiva, the thin membrane covering the eyelid and the front surface of the eye.

There are two types of infectious conjunctivitis – bacterial and viral.

If your child has conjunctivitis, they’re not alone. About 12% of kids get bacterial conjunctivitis every year. This highly contagious condition affects children and adults. In addition to reddish eyes, the following symptoms are associated with conjunctivitis:

  • Bacterial conjunctivitis – irritated eyes, swollen eyelids, eye discharge, crusty eyelids and excessive tearing
  • Viral conjunctivitis – cold or flu-like symptoms, runny nose, fever, itchy eyes, excessive tearing

If you or your child are experiencing these symptoms, it’s important to schedule a prompt appointment with an eye doctor, who can diagnose whether the conjunctivitis is viral, bacterial or due to allergies.

Depending on the diagnosis, your eye doctor will prescribe antibiotic eye drops or creams to treat bacterial conjunctivitis. The viral form may run its course after a few days, but cold compresses and non-prescription eye drops may provide relief.

Dry Eye Syndrome

If your eyes are chronically bloodshot you may have dry eye syndrome (DES). Signs of DES include:

  • Dry, irritated eyes
  • Burning or stinging eyes
  • Discharge from the eyes
  • Light sensitivity
  • A feeling you have something stuck in your eyes
  • Blurred vision
  • Watery eyes

Dry eye syndrome is most commonly caused by a blockage of the tiny meibomian glands in the eyelids. These glands secrete oil that keeps eye moisture from evaporating too quickly. Without the oil, tears dry fast, leaving your eyes feeling dry, itchy and with a bloodshot appearance.

Too much screen time, aging, certain medications such as antihistamines, and medical conditions such as Sjogren’s syndrome can cause dry eye syndrome.

In addition to any medications or in-office treatments your eye doctor recommends, make sure to get plenty of hydration, take frequent breaks from digital screens and use a humidifier in your home.

Uveitis

In addition to bloodshot eyes, if you also experience blurred vision, see floaters or your eyes feel painful, you may have an eye inflammation called uveitis. The causes of uveitis include:

  • Autoimmune or inflammatory condition
  • Infection
  • Medication side effects
  • Cancer (in rare cases)

Unfortunately, uveitis symptoms can often be mistaken for something less serious. That’s the reason it’s important to get an eye exam if your eyes are bloodshot. Left untreated, uveitis can lead to serious conditions such as retinal scarring, cataracts and vision loss.

Depending on the cause and severity, your eye doctor may treat uveitis with prescription eye drops, steroid pills, injections or eye implants.

Eye Injury

It’s vital that all eye injuries receive immediate eye care from an eye doctor.

Even a minor eye injury can cause a big red blotch to form on the white part of the eye (sclera). The cause is a broken blood vessel or a subconjunctival hemorrhage.

Although the appearance of this blood looks severe, and can make the entire white part of the eye appear bright red, a subconjunctival hemorrhage is usually painless and doesn’t cause vision loss. Any time you notice excessive blood on the eye following an eye injury, schedule an appointment with an eye doctor to assess the health of your eye.

Glaucoma

In rare cases, bloodshot eyes may signal the presence of glaucoma – a leading cause of vision loss and blindness.

While some types of glaucoma don’t show symptoms in the early phases, bloodshot eyes can indicate the type of glaucoma that requires immediate medical care. This disease causes damage to the optic nerve due to excessive pressure within the eye. When this pressure suddenly rises, the eye’s blood vessels become dilated and visible, making the eye appear red.

If you have bloodshot eyes and/or have the following risk factors for glaucoma, immediately schedule an appointment with your eye doctor.

  • Family history of glaucoma
  • Aged 60+
  • African American, Asian or Hispanic
  • Diabetes
  • High blood pressure

Bloodshot Eyes Won’t Go Away?

Talk to Us Any time you notice bloodshot eyes or blood on the front of the eye, don’t wait. Schedule your eye exam with Dr. Terry Tsang at Dr. Terry Tsang Optometry, Inc. in Irvine today.

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Can I get bloodshot eyes after LASIK surgery?

LASIK surgery is highly effective minimally invasive laser eye surgery that can correct refractive errors, but like all surgical procedures, it can have side effects. Your eyes may be bloodshot or you could see halos from a few days to three weeks after surgery. Additionally, you may experience other dry eye symptoms. Eye drops and liquid tears can alleviate these symptoms, but if you have any concerns about your eyes following LASIK surgery contact your eye surgeon.

What Should I Expect from a Glaucoma Exam?

If you have a family history and/or other risk factors for glaucoma, and if your eyes look bloodshot, consider scheduling a glaucoma exam. Your eye doctor may perform the following tests:

  • Tonometry – eye pressure test
  • Gonioscopy – to see how fluid is draining out of your eye
  • Vision field test – to examine the functioning of the optic nerve
  • Dilated pupil exam – to detect any damage to the optic nerve
  • Retinal photo or OCT – digital examination of the retina and optic nerve health

What’s Your Optometrist Role in Cataract Surgery?

If you’re over the age of 60, there’s a good chance you’ll develop cataracts sometime in the next 20 or so years. While the only effective long-term treatment for cataracts is surgery, it can take years or even decades for a cataract to reach the point where it needs to be surgically removed.

In the meantime, your optometrist can monitor its progression, manage your symptoms and ensure you have the best vision possible. Once your cataract makes it difficult for you to function day-to-day, your eye doctor will refer you to an ophthalmologist who will perform eye surgery to replace your eye’s natural lens with a clear artificial lens.

Following your surgery, your optometrist will co-manage your post-op recovery in coordination with your eye surgeon.

Your Optometrist Will Discuss Cataract Treatment Options

A cataract, a clouding of the eye’s natural lens caused by the breakdown of proteins in the lens, leads to progressively blurry vision. So if you’ve been diagnosed with a cataract but aren’t yet ready for surgery, you’ll be having regular contact with your optometrist, who will explain the condition, discuss your treatment options and help manage your symptoms.

Once you’re diagnosed with cataracts, you may want to slow the progression of the condition. Working with an optometrist who knows your personal and family health history as well as your various options for cataract management and surgery is a massive advantage, as your optometrist can give you advice on dietary and lifestyle changes.

The Importance of Regular Eye Exams

Regular eye exams are important for everyone, and particularly if you’ve been diagnosed with cataracts. Because the cloudy areas on your eye lenses will worsen with time, your optometrist will carefully monitor your vision and upgrade your glasses or contact lens prescription as needed. Your optometrist will perform a visual acuity test and other tests to gauge increased sensitivity to light and glare, as well as deterioration in your contrast and color vision.

When’s It Time for Cataract Surgery?

At some point, your optometrist may determine that your cataracts are severe enough to require surgery. That’s typically when options to correct your vision — updated prescriptions and speciality filters that block glare and increase contrast vision — are no longer sufficient to give you the vision you need.

Your optometrist can recommend an ophthalmologist and provide information about what to expect during cataract surgery. You’ll see your eye surgeon for post-surgery check-ups, and your optometrist for long-term eye care.

If your vision is blurred or if you notice a cloudy patch forming on your eye, you may have developed cataracts. For optimal vision care and cataract management, make sure to schedule an appointment with Dr. Terry Tsang at Dr. Terry Tsang Optometry, Inc. in Irvine today.

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What’s the best treatment for cataracts?

Although many people use glasses to manage cataract symptoms and improve their deteriorating vision, the only way to really treat cataracts is via surgery. You may want to delay the procedure, but once your quality of life is affected to the degree that it’s difficult to drive or perform everyday tasks, it’s time to have cataract surgery.

Will cataracts return after surgery?

Generally, no. Because the eye’s natural lens is removed and replaced with an artificial one during cataract surgery, a cataract can’t return to that eye. That said, there’s a possibility that a few years after the surgery, you may need a quick laser procedure if the proteins on the lens capsule — the layer that holds the artificial lens in place — becomes cloudy.

5 Vision-Saving Tips for National Save Your Vision Month

March is here. And you know what that means…

It’s National Save Your Vision Month!

In honor of this special month, which not only signals the start of spring but reminds us to protect our eyes, we’ve put together a list of 5 essential ways that you can ‘save your vision.’

It goes without saying that routine eye exams are a top priority when it comes to taking care of your eyes, so here are 5 additional things you can do to keep your eyes healthy and your vision clear.

1. Maintain a Healthy Diet

You’re likely aware that a balanced diet consists of all different types of nutritious foods that contain the vitamins and nutrients you need to keep your body healthy and strong.

But did you know that certain foods actually promote eye health and can lower your risk of eye disease?

Eating foods that are high in omega-3 fatty acids, lutein and zeaxanthin, as well as vitamins A, B, C and E, can protect your eye health and help save your vision from sight-threatening eye diseases, like age-related macular degeneration (AMD), diabetic retinopathy and glaucoma.

If you don’t think your daily meals offer enough of these essential vitamins and nutrients, ask your doctor whether you should add a daily supplement to your diet.

2. Limit Screen Time

The digital world has created a new venue for working, communicating, socializing and entertainment. But it’s also brought about a new eye condition called computer vision syndrome (CVS) — also called digital eye strain (DES) — that’s a growing concern among eye care professionals.

Not only can too much screen time affect productivity in work and school, but it can also result in dry, red, irritated eyes, blurry vision, headaches, neck, back and shoulder pain, and even have a negative effect on your mood and quality of sleep.

So this month, take it upon yourself to be more aware of how much time you spend in front of a digital screen, and try to set boundaries whenever possible for you and your children. You can also practice the 20-20-20 rule — every 20 minutes, look at something at least 20 feet away for a minimum of 20 seconds.

3. Use Protective Eyewear

Every day, thousands of people receive emergency care for an eye-related accident — many of them resulting in permanent damage and vision loss.

The best way to protect yourself and your loved ones is by wearing protective eyewear for all activities that pose an eye health risk — from sports and water gun fights to lightsaber tournaments and science experiments. And, of course, this also implies any type of home-improvement project that involves small particles like grass, saw dust or metal flying into your eye.

Protective eyewear can truly save your vision.

4. Wear Sunglasses All Year Round

Sunglasses are more than just a fashion accessory to enhance your look. They shield your eyes from the sun’s harmful UV rays, which can damage your vision and lead to serious eye diseases like cataracts and macular degeneration.

Now you have an even better excuse to go out and buy yourself the new pair of shades you’ve been dreaming about. Just make sure they offer 100% UV protection.

Wear your new sunglasses all year round, even on cloudy and snowy days, because the sun’s UV rays can penetrate the clouds and reflect off the snow-covered ground, doubling your exposure.

5. Quit Smoking

If you’ve been thinking about quitting, now’s the time! Smoking is not only dangerous for your overall health, it increases your risk for sight-threatening eye diseases like glaucoma, diabetic retinopathy, age-related macular degeneration and cataracts.

So, for the sake of your vision and overall health, take the first steps toward kicking your smoking habit.

In honor of National Save Your Vision Month, why not try some of these vision-saving habits that can help you keep your eyes and vision healthy for a lifetime. Your future self will thank you.

Interested in learning more about how you can protect your eyes and vision? Contact Dr. Terry Tsang Optometry, Inc. in Irvine today to schedule an appointment. We’ll be happy to answer any of your questions and to offer you the best possible eye care.

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Do children need to wear sunglasses?

Yes, sunglasses are essential for protecting your child’s eyes both now and in the future. A child’s eyes are still maturing and are therefore even more susceptible to UV damage than adults. Encourage your child to wear sunglasses whenever they play outside by setting a good example and making sure to wear sunglasses whenever you venture outdoors.

What are sports goggles?

Sports goggles are a type of protective eyewear worn by many athletes. These goggles contain impact resistant, durable polycarbonate lenses, offering the ultimate eye protection during sports activities. If you or your child play sports, sports goggles are an essential accessory to your athletic gear.

10 Ways to Give Your Eyes Some Love This Valentine’s Day

Valentine’s Day is the time to express your love and appreciation to those you care about most. But it’s also a great opportunity to take the time to pamper yourself — so why not start with your eyes?

Practice these 10 healthy lifestyle habits to help protect your eye health and vision.

1. Be Mindful of the Food You Eat

Fill your plate with fresh fruits and veggies, lean proteins and whole grains. A well-balanced diet is good for your body and can lower your risk of eye disease.

Studies show that foods high in vitamins A, C, E, Omega-3, lutein and zeaxanthin are especially beneficial for promoting eye health.

2. Drink Plenty of Water

Drinking at least eight 8-ounce glasses of water each day will keep your body hydrated and your eyes moist — which is essential for preventing dry eye syndrome. To add some flavor to your water, try adding a splash of lemon juice or swap some of those glasses of water for an herbal tea or other non-caffeinated beverage. Caffeinated drinks have a dehydrating effect, so try to limit your coffee consumption as much as possible.

3. Exercise Regularly

Exercise is widely known for its physical and mental health benefits, but studies show that it can also lower your risk of serious eye conditions and diseases. Cardio exercise in particular has been shown to lower eye pressure and improve blood flow to the retina and optic nerve at the back of the eye. So grab your gym bag and get moving!

4. Don’t Smoke

If you’ve been thinking about quitting, there’s no better time than now. Smoking tobacco significantly raises your risk of developing sight-threatening eye diseases like diabetic retinopathy, cataracts and age-related macular degeneration (AMD), and can also lead to their early development.

Smoking also robs the body of the essential vitamins and minerals it needs to maintain eye health, and contains around 7,000 chemicals that can lead to eye irritation and dry eye.

5. Practice Good Makeup Hygiene

While wearing makeup can accentuate your eyes and make you feel more beautiful, it’s important to note that if not used properly, certain makeup products can adversely affect eye health.

To keep your eyes and vision healthy, make sure to:

  • Clean your brushes and applicators regularly
  • Toss any expired products, or eye makeup you’ve used during an eye infection
  • Only apply makeup to the outer margin of your eyelids
  • Remove your makeup before going to bed
  • Never share makeup or use in-store testers

Following these safety tips will help to lower your risk of eye infections and other serious complications.

6. Wear Sunglasses

Studies show that prolonged UV exposure can damage the eyes and lead to the development of sight-threatening eye conditions, like cataracts, macular degeneration and glaucoma, in the future.

Purchase a pair of stylish sunglasses with 100% UV protection and wear them any time you venture outdoors — the sun’s UV rays can penetrate the clouds and reflect off of snow, sand, water and pavement. So keep a pair of sunglasses next to your front door and a spare pair in your bag or car to ensure you have UV protection wherever you go. d

7. Prevent Eye Injuries

About 90% of vision loss from eye injuries can be prevented by wearing the right eye protection.

Protective eyewear like sports goggles or glasses with polycarbonate lenses are designed with sturdy materials that are less likely to break or shatter while you play sports, and can protect your eyes from small particles that fly in the air when you mow the lawn or engage in DIY projects.

8. Learn First Aid for Eye Injuries

Let’s be real, accidents can happen even if we take all the right measures to protect ourselves. But knowing what to do in case of an unexpected eye injury can potentially save you or someone you love from permanent eye damage or vision loss.

Note: Any type of eye injury should be taken seriously, and promptly examined by an eye doctor.

9. Avoid Digital Eye Strain

Prolonged screen time can cause eye strain, dry eyes, blurry vision and headaches — and lead to a condition called digital eye strain, also known as computer vision syndrome.

Avoid symptoms of digital eye strain by limiting screen time as much as possible. If prolonged screen time is unavoidable, practice the 20-20-20 rule: set an alarm on your phone as a reminder to take breaks every 20 minutes to focus on an image at least 20 feet away, for at least 20 seconds.

10. Visit Your Eye Doctor

Regular eye exams are crucial when it comes to maintaining your eye health. With an eye exam, your eye doctor can identify early signs of sight-threatening eye diseases and conditions — enabling earlier treatment and increasing your chances for optimal results.

From all of us at Dr. Terry Tsang Optometry, Inc. in Irvine, we wish you a Happy Valentine’s Day!

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What’s the difference between an eye exam and vision screening?

Vision screenings are basic tests of visual acuity, generally conducted by a school nurse or pediatrician. These screenings can’t identify many vision conditions that impact learning or work performance, and are unable to detect ocular health problems.

A comprehensive eye exam, which is performed by an eye doctor, includes tests for visual acuity and functional vision, as well as close examination of the inner and outer structures of the eye.

How often do I need to have an eye exam?

According to the American Optometric Association (AOA), it is important to have your eyes examined every one to two years, depending on your age, whether or not you wear glasses or contacts, your family history of eye disease, and your ocular health to date. Annual eye exams help your eye doctor monitor your eye health and easily identify any changes in your vision.

4 Reasons Why 3D Vision is So Important

Woman Covering One Eye to Test 3D VisionOur sense of depth perception and ability to see in 3 dimensions are often-overlooked benefits of our complex visual system.

Our eyes gather a significant amount of visual data as we observe our surroundings. Both eyes send this gathered data back to the brain, where it is interpreted and combined into a single cohesive image.

The fact that the eyes are set a small distance apart from each other allows them to gather slightly different sets of visual information, which the brain interprets as depth and distance when combining the two images. This produces 3-D vision.

Here are our top 4 reasons why 3D vision is so crucial:

1. Learning

3D vision plays a key role in a child’s ability to learn in school. Children who have problems with 3D depth perception will often have difficulty with spatial skills and visualization. This impacts their ability to form letters correctly, develop accurate word memory and easily understand complex shapes. These challenges can significantly undermine their reading speed, spelling abilities, handwriting, understanding of mathematics and comprehension.

3D vision is especially important in subjects such as geometry, where a sense of depth and space are essential to understanding basic concepts.

2. Sports

In sports like basketball, football and soccer, it’s essential to know where other teammates are standing on the field or court in order to pass the ball. It’s also a key part of catching incoming passes and judging the distance to the basket or goal post.

In baseball, 3D vision is necessary for sizing up the ball as it comes across the plate, for judging distances, swinging, catching and hitting, and running the bases.

3. Driving

Driving safely is absolutely tied to depth perception and the ability to see in 3D. Without them, drivers may not be able to avoid hitting other cars, know when it is safe to change lanes, and how far to go when backing into or moving out of parking spots to avoid other cars, the curb or pedestrians.

Accurate 3D vision is particularly important at night, where there are fewer visual cues, such as the size and movement of nearby objects, to make quick decisions.

4. Day-To-Day Tasks

Even the most basic day-to-day tasks, such as shaking another person’s hand, are made easier with proper depth perception and 3D vision.

3D vision also makes the world around you safer. Crossing the street requires you to estimate the distance between yourself and any cars that may be on the street, as well as the speed those cars are traveling. Even walking downstairs can be hazardous if you can’t properly gauge the distance from each step down to the next.

Your Eye Doctor Can Help With 3D Vision Issues

If you’re experiencing difficulties with 3D vision, speak to your eye doctor about vision therapy. This doctor-prescribed, evidence-based regimen of in-office and at-home eye exercises helps reset and strengthen the connection between your eyes and your brain. For 3D vision, this means helping coordinate the signals coming from your brain to each eye, so that the eyes can move and focus in unison.

For more information about 3D vision, and how our eye doctors can help, visit Dr. Terry Tsang Optometry, Inc. today.

 

Frequently Asked Questions with Dr. Terry Tsang

Q: How can vision therapy help with 3D vision issues?

  • A: After we perform a functional eye exam to confirm that vision therapy is the right choice for you or your child, we’ll begin creating a customized therapy program for your specific needs. The vision therapy program will help strengthen the connection between the eyes and brain, to help the entire visual system work together more effectively and efficiently. In the case of 3D vision issues, this may mean working on helping the eyes move in unison more effectively or improving the eyes’ ability to converge effectively on objects close-up.Though vision therapy can sometimes take a while to address the problem (4 to 6 months on average), it is usually quite successful.

Q: What is the difference between a functional eye exam and a standard eye exam?

  • A: A standard eye exam will check for visual acuity and the presence of eye disease. However, a standard exam doesn’t assess eye teaming, convergence/divergence and other problems affecting 3D and binocular vision. That’s why a functional eye exam is so important. If your child is behind in school or having developmental issues, these may be tied to vision problems that can be detected as part of a functional eye exam.

Our practice serves patients from Tustin, Lake Forest, Newport Beach, and Mission Viejo, California and surrounding communities.

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Double Vision After Brain Surgery

Double Vision After Brain Surgery 640×350Double vision (diplopia) can occur after a traumatic brain injury, a stroke or certain types of surgery due to a disruption in the connection between the nerves and extraocular muscles that control the eyes’ position and movements.

Diplopia following brain surgery is usually temporary and can take a few days or weeks to resolve, depending on the source of the problem. In the meantime, people who suffer from double vision after an operation can benefit from specific glasses and neuro-optometric rehabilitation through eye exercises that help restore single vision.

If you are experiencing diplopia after brain surgery and want to know which treatment is right for you, make an appointment with at today.

What Causes Double Vision After Brain Surgery?

The brain is connected to the eyes through a network of nerves — including the optic nerve — that controls the movement and alignment of the eyes. These nerves can be impacted by brain disorders, tumors and strokes, or during brain cranial surgery. Brain surgeries can disrupt the connection between the brain and the eyes, resulting in the misalignment of the eyes and double vision.

Alternatively, the muscles surrounding the eyes that keep the eyes aligned and focused can be damaged during surgery, affecting their ability to perform accurately and effectively.

Ordinarily, having two eyes means the brain receives two images, which it converts into one single 3D image of the world. However, an injury to the eye muscles can cause an eye misalignment, making it impossible for the brain to fuse the two images into one single, clear image — resulting in double vision.

What Are Other Symptoms of Damage to the Visual System?

Although the most obvious sign of damage to the visual system after brain surgery is double vision, patients may experience any of the symptoms below:

  • Eyestrain
  • Crossed eyes
  • Headaches
  • Pain when moving the eye
  • Droopy eyelids
  • Nausea
  • Eye weakness

How to Treat Diplopia After Brain Surgery

There are several treatments for diplopia after brain surgery.

Prism glasses

After an eye exam your eye doctor may prescribe prism glasses that work by altering the path of light rays and compensate for any misalignment of the two eyes. These lenses allow the brain to fuse the two images from the eyes to create a clear and single 3D view of the world around us.

Eye Patches

Your eye doctor may recommend wearing an eye patch because it removes the second image from a weaker eye reaching the brain. Using a patch can temporarily remove the visual disturbance and prevent you from seeing double images, but is often not the best long-term solution. It is important to follow a precise regimen for eye patch wearing and not deviate from the instructions without first consulting your doctor.

Neuro-Optometric Rehabilitation

One effective way to regain clear and comfortable vision after brain surgery is through neuro-optometric rehabilitation, which is a personalized eye exercise program that will strengthen the connection between the brain and your eye muscles, with the goal of improving your quality of life by regaining your clear 3D vision.

Following a functional vision evaluation to assess visual problems, your optometrist may prescribe customized exercises to re-establish the effective communication between your eyes and brain.

How Long Will It Take to Recover from Diplopia?

Usually, diplopia that develops following surgery is temporary, and with treatment, regular vision can be restored in days or weeks. In cases that persist, eye patching, prism glasses and neuro-optometric rehabilitation usually resolve diplopia within weeks or months. In rare cases, eye surgery may be required to correct diplopia.

If you are experiencing double vision after brain surgery, schedule an appointment with today.

Our practice serves patients from Tustin, Lake Forest, Newport Beach, and Mission Viejo, California and surrounding communities.

Frequently Asked Questions with Dr. Terry Tsang

Q: What are the different types of diplopia?

A: All types of diplopia involve seeing two images, but there are different forms of diplopia, depending on the positioning.

  • – Horizontal diplopia – images are separated laterally
  • – Vertical diplopia – one image is higher than the other
  • – Monocular diplopia – diplopia continues in one eye when the other is closed.

Monocular diplopia can be caused by conditions such as astigmatism, cataracts or keratoconus. Diplopia can be temporary, intermittent or constant.

Q: What are the common causes of diplopia?

A: Diplopia can be caused by the following: Brain trauma or brain tumor

  • – Stroke
  • – Eye problems like keratoconus, dry eye and cataracts
  • – Brain surgery
  • – Cranial nerve palsy
  • – Eyestrain

Why Goalkeepers Need Strong Visual Skills

Goalkeeper blocking a goalSports require athletes to be in peak physical condition to play at their best. This doesn’t just include arms and legs, but eyes too. This is especially true for goalkeepers, who need lightning-fast reflexes and incredibly accurate vision skills to guard the goal and catch or deflect the puck or ball and prevent that scoring shot.

Our eye care professionals at Dr. Terry Tsang Optometry, Inc. can help goalies and other athletes, both amateur and pro, improve their functional vision with sports vision training.

What Visual Skills Does a Goalkeeper Need?

Goalies need to master a range of visual skills in order to prevent the opposing team from scoring. Convergence and divergence, as well as the ability to alternate between them quickly and accurately, are among the most important.

Convergence

Convergence is the eyes’ ability to efficiently and accurately focus on an object as it moves toward you, and up close. Professional soccer players send the ball flying at the net at an average of 70 miles per hour, and a hockey puck in the NHL can be slapped at the goal at a blistering 100 miles per hour. This means that for penalty shots and other fast-moving, close-up plays a goalkeeper’s eyes can have mere fractions of a second to accurately converge on the ball or puck before the goalkeeper needs to decide where to move their body and how to react.

Poor convergence can mean that the goalie’s eyes are too slow to converge on the target, or that they don’t converge accurately, leading to double vision as the ball or puck is incoming.

Either of these situations can make it difficult, if not impossible, to make the save during a fast-paced play.

Divergence

Divergence is the eyes’ ability to efficiently and accurately focus on objects at a distance, and as they move away. This skill is vital for goalkeepers, who need to save shots taken from halfway down the field or ice, and to accurately judge the position and flight of the ball or puck. Divergence also allows the goalkeeper to track shots that rebound out, as well as the movements of the puck or ball in case the opposing team quickly takes another shot.

Poor divergence makes it challenging for the goalie to find or track the target from farther out, or as it moves away from them, from close range into the distance.

Alternating

Being able to efficiently alternate between convergence and divergence is also vital in a fast-moving game. Consider the following play-by-play:

  • Using divergence, a goalkeeper can track a ball or puck from far down the field or ice, until a shot is taken.
  • As the shot comes closer in, they engage their convergence to track it moving toward them.
  • They make a successful save, resulting in a rebound out. Divergence is engaged as the ball or puck moves away from them once again.
  • Within fractions of a second, an opposing player may recover the puck or ball, and attempt another shot. The shot is incoming again, and convergence is re-engaged.

The goalkeeper has only seconds or even fractions of a second to respond, re-focus, and respond again.

How Can Sports Vision Training Help?

Sports vision training is a personalized regimen of eye exercises prescribed by eye doctors to help athletes perfect the visual skills that are most essential for their sport.

Working through the prescribed exercises retrains the athlete’s brain to work faster and more effectively with their eyes, improving convergence, divergence and other visual-motor and spatial skills.

Sports vision training can help goalkeepers of all ages and abilities gain the visual skills they need to stay on top of their game, block shots and save the day.

Have questions about how we can help you play your best game? Visit us or call our office today.

Our practice serves patients from Tustin, Lake Forest, Newport Beach, and Mission Viejo, California and surrounding communities.

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Find Out If Sports Vision Is Right For You 949-870-2763

Sports Vision Exercises to Try At Home

woman and her daughter exercising at homeNote: the activities here do not replace an eye exam and in-office sports vision training program from an eye doctor experienced in sports vision.

When athletes consider the skills they need to succeed, agility and strength often come to mind. But those aren’t the only skills that matter. Many athletes don’t realize that, when it comes to conditioning, their eyes are an important asset.

An athlete’s capacity to notice, understand and respond to events on the field, both near and far, has a substantial influence on the quality of their play. The intricate capabilities of their visual system are required to dunk that basket, return that serve, receive that pass or knock it out of the ballpark.

There is an entire area of optometry that provides sports vision training, with research to back it up. According to a study published by the Journal of Sports Science and Medicine, visual abilities like peripheral perception and reaction time can be improved by means of appropriate visual training.

Sports vision exercises can help improve your peripheral vision, visual memory, hand-eye coordination and much more. Who wouldn’t want to improve their game by doing eye exercises?

Sports Vision Training Exercises at Home

Your eye doctor will recommend an in-office sports vision training program for you based on the sport and the visual abilities you want to develop. Here are some very basic exercises you can do at home until you get to your optometrist’s office.

While home-based exercises are a good first step toward upping your performance, they aren’t a substitute for a sports vision training program designed by an optometrist that is tailored to your individual strengths and weaknesses.

20-20-20 Rule

Your eyes, like your body, need to be as agile as possible. Switching your focus between near and distant objects is a simple way to enhance your focusing skills at home. Look up from your computer and focus on anything 20 inches away, then something farther away, such as looking out a window.

Most sports rely on the ability to change focus from near to far objects, such as a ball or other players.

Visual Memory Games

One way we understand and comprehend information is via visual memory. It’s all about recalling where players are on the field when receiving a pass, or how much spin or curvature the ball had during the previous play. When you play memory games like a children’s matching game, you’re teaching a part of your brain to remember information accurately and quickly. Playing memory games can help improve your speed.

The Turning Tray

Practice reading words in motion. Attach a piece of paper with words to a turning tray and move it at different speeds. Alternatively, attach the paper to a moving door or a bouncing ball. Experiment with font, color, size and familiarity of words to see how many you can read and how quickly.

This exercise can help improve your dynamic visual acuity, which is needed in fast-paced sports like hockey, basketball and tennis. Athletes who play these sports need to be able to see objects clearly while they are moving quickly.

Sidelong Glance

Peripheral vision allows you to see another player from the opposing team rushing toward you, or where your teammate is preparing to pass, from the edge of your visual field. When you’re using a computer or walking outside, practice ‘viewing’ from the sides of your eyes, both right and left. Look for details in your peripheral vision or lean your head to one side to ‘scan’ the activity with a sidelong glance.

One-Eyed Monster

Depth perception is one of the most essential visual tricks your binocular vision provides. This helps you know how far the goal post is. Train each eye separately by kicking or catching the ball with only one eye open. Alternatively, practice this skill by holding a drinking straw at arm’s length and trying to drop a tiny pebble or balled-up piece of paper through the straw with your free hand.

Ping-Pong

Ping-Pong, or table tennis, isn’t just a classic fun game, it’s an excellent way to enhance your eye-hand coordination. It’s a fast-paced game that trains the brain to determine the speed of a moving object and respond accordingly.

Ready to improve your game? Schedule an appointment with Dr. Terry Tsang Optometry, Inc., where our eye doctor will assess your visual skills and design a customized sports vision training program to boost your performance in your chosen sport.

Our practice serves patients from Tustin, Lake Forest, Newport Beach, and Mission Viejo, California and surrounding communities.

Frequently Asked Questions with Dr. Terry Tsang

Q: What is sports vision training?

  • A: Sports vision training is a custom-made program that enhances communication between the brain, body, and eyes when participating in sports. Athletes, both professional and amateur, benefit from sports vision training because it helps them process information and react faster and more accurately to what they see on the field.Sports vision training involves a set of strategies and exercises that teach the brain and body to respond to what the eyes see more efficiently and accurately.

Q: Is sports vision training beneficial for everyone?

  • A: Whether you play basketball, football, hockey or tennis, sports vision training is perfect for anyone of any age seeking to take their performance to the next level.

Request A Sports Vision Appointment
Find Out If Sports Vision Is Right For You 949-870-2763

6 Things To Know About Keratoconus

happy couple in winterKeratoconus is an eye disease that causes the cornea, the clear dome-shaped front surface of the eye, to become misshapen and bulge. This progressive disease usually occurs in both eyes and affects approximately 50-200 in every 100,000 individuals.

People who have keratoconus often experience problems like blurred vision, distorted vision, night blindness and sensitivity to light. Clear vision correction for keratoconus can be challenging to achieve because the irregular corneal shape makes it difficult or impossible for standard eyeglasses or contact lenses to provide you with sharp vision.

Thankfully, there are ways for people with keratoconus to achieve clear and comfortable vision, something we explore below, along with several other key points about keratoconus.

1. Everyone has different risk factors for developing keratoconus

Some risk factors for developing keratoconus include:

  • Hereditary predisposition
  • Eye rubbing
  • Other medical conditions like Down syndrome, allergic dermatitis and connective tissue disorders
  • Eye inflammation

2. Keratoconus can develop at any age

Although most cases of keratoconus are first diagnosed in adolescence or young adulthood, it can appear during any stage of life. That’s why regular eye exams are crucial, even if your vision seems clear and your eyes appear to be healthy.

3. Early diagnosis is key

This rings true for almost every eye disease, especially keratoconus. Catching it early in its tracks can allow the eye doctor to implement various treatments to slow down its progression during the initial stages, when this condition tends to worsen more rapidly.

4. Keratoconus progresses at different rates throughout life

Keratoconus progression varies from person to person, and one person can experience varying degrees of progression in each eye. Some patients live with mild keratoconus their entire lives, while other patients develop severe keratoconus early on.

Often, optometrists will recommend that patients undergo certain procedures to strengthen the cornea and prevent or slow down further progression.

5. Keratoconus can be treated with surgery or scleral contact lenses

Corneal cross-linking surgery is an effective option to provide enhanced strength to the cornea and is the only FDA-approved method of stopping or slowing keratoconus progression. However, if the condition develops into severe keratoconus, a corneal transplant may be the best option for treating the condition and restoring clear vision.

Scleral contact lenses offer another option to surgery. They are ideal for patients with early or moderate levels of keratoconus because they safely and effectively correct vision without irritating the misshapen cornea. In fact, studies have shown that patients with keratoconus who wear scleral contact lenses greatly reduce their risk of needing keratoplasty (corneal transplant surgery).

The large diameter of scleral contact lenses allows them to vault over the sensitive corneal tissue and then also coat the cornea in a nourishing reservoir of fluid for optimal comfort and visual clarity. Because eye rubbing and corneal irritation are significant risk factors for the progression of keratoconus, the protective qualities of scleral lenses can help to minimize keratoconus progression.

6. You can live a normal life with keratoconus

With the proper care and treatment from your optometrist, keratoconus shouldn’t stop you from living your life to the fullest. Although it can be discouraging to experience vision problems that can’t be resolved with standard lenses or glasses, know that there are other options available.

At Dr. Terry Tsang Optometry, Inc., we help patients with keratoconus and other corneal abnormalities achieve crisp and comfortable vision using scleral contact lenses and other specialty lenses.

Our practice provides scleral lenses to patients from Tustin, Lake Forest, Newport Beach, and Mission Viejo, California and surrounding communities.

Frequently Asked Questions with Dr. Terry Tsang

Q: Who else can benefit from wearing scleral contact lenses?

  • A: Scleral contact lenses are ideal for patients with any of the following conditions: corneal abnormalities, severe dry eye syndrome, post-LASIK or corneal transplant, eye allergies, high refractive error or corneal trauma. Speak with your optometrist to find out if scleral lenses are right for you.

Q: Do all optometrists fit specialty contact lenses like sclerals?

  • A: No. If you are interested in scleral contact lenses, be sure to choose an optometric practice that has years of experience fitting specialty lenses. At Dr. Terry Tsang Optometry, Inc., we have the knowledge, skill and experience necessary to provide you with the best lenses for your eyes. Call us to learn more or schedule your scleral lens fitting.

Request A Scleral Lens Appointment
Can Scleral Lenses Help You? Find Out! 949-870-2763