The Science Of Sunglasses

Have you ever wondered just what sunglasses do for your eyes, and how? It’s a little more complex than just dropping a dark filter over your vision.

Different Tints Do Different Things

Did you know that the color of your sunglasses’ lenses affects what they do for your eyes? This goes beyond just putting a color filter on your field of vision; different colours actually serve different purposes:

• Yellow and amber lenses are ideal for outdoor sports, particularly snow sports, as they filter out blue light, which may be harmful to your vision, and they reduce glare off the snow while improving contrast and depth perception.
• Rose and purple lenses increase contrast of objects against a blue or green background, which makes them great for hunting or water skiing.
• If you don’t want the colors you see to be altered by your lenses, you’ll probably prefer sunglasses with gray, black, or green lenses. Green lenses have the added benefit of filtering out blue light.

Glare Elimination With Polarized Lenses

Polarized lenses are particularly effective at getting rid of glare. Think of them as windows that have microscopic slats. Light can only enter from certain directions, so light bouncing off shiny or bright objects around you can’t get past the lenses!

A quick way to tell whether lenses are polarized or not is to hold them up to a light source and slowly rotate them to see if the light coming through changes. If it does, they’re polarized and will protect your eyes from glare!

Cheap Sunglasses Are Dangerous

A cheap pair of sunglasses might look cool and save you from having to squint your way through a sunny day, but you could actually be putting your eyes in more danger by wearing them than you would if you simply went without. You might think that as long as the sunglasses are dark enough, you’ll be fine from eye-damaging UV radiation. Not so!

What makes these sunglasses worse than no sunglasses at all is that the dark tint tricks your eyes into dropping their guard. You won’t squint and your pupils will dilate, letting in all those harmful rays that squinting and contracted pupils offer some protection against.

That’s where high-quality and prescription sunglasses come in. UV protection is one way you get what you pay for. Prescription sunglasses have it, and you can check the labels of non-prescription pairs to make sure they do. Only buy sunglasses that offer 99 to 100 percent UV protection or up to 400nm UV protection!

Any Questions?

Is there anything else you’d like to know about sunglasses, the protection they offer, and how to choose the right pair for you? Don’t hesitate to ask!

Wishing our patients an awesome summer!

Risks Associated With Sun Exposure

Ultraviolet (UV) radiation is an invisible component of sunlight that is most commonly known to cause sunburns and skin cancers. While some UV is filtered by the ozone layer, increasing amounts are reaching the earth as the ozone layer steadily diminishes. Because exposure to UV is cumulative, direct contact with sunlight for even short periods of time can cause several long-term eye health problems, many of which begin symptom-free.

To help reduce UV radiation damage to your eyes, consider the following tips:

• Beware of high sources of UV exposure in the workplace. The Canadian Center for Occupational Health & Safety indicates examples of workers at potential risk from exposure to UV radiation including outdoor workers, construction workers, paint and resin curers, plasma torch operators, welders, farmers, food and drink irradiators, hairdressers, laboratory workers, lighting technicians, lithographic and printing workers and police.
• Recognize sources of man-made ultraviolet radiation. Examples include various types of UV lamps, arc welding torches and mercury vapour lamps. In dental and medical practices, UV radiation can be used for killing bacteria, creating fluorescent effects, curing resins and phototherapy. Sun tanning booths also use UV radiation.
• Wear sunglasses, prescription or safety glasses with anti-UV coatings. Sunlight is by far the greatest source of UV radiation.

Exposure to its UVA and UVB rays, as well as man-made sources of UVC rays, can lead to long-term eye damage including:

• Age-related macular degeneration
• Cataracts
  • Eyelid skin cancer
  • Premature age spots around the eyes
  • Tissue growths on the surface of the eye including pinguecula and pterygium, of which the latter can encroach on the corneal axis

• If you wear corrective contact lenses, consider wearing UV-blocking contact lenses for an added layer of UV protection. Sunglasses are important, but aren’t always enough. Depending on the frame size, shape and position, as much as 45 per cent of UV rays can still reach the eyes of people wearing some sunglasses. Contact lenses with UV protection are an effective way to block light that gets in the sides and protects from harmful UV radiation reaching the cornea and into the eye. Not all contact lenses offer UV protection so check with your doctor of optometry to find out which ones are right for you.
• Recognize symptoms of UV eye damage, including immediate pain, inflammation of the cornea and an aversion to light. UV burns are commonly known as welder’s flash, snow blindness, ground-glass eyeball, or flash burn, depending on the UV source. Should you experience these symptoms, see your doctor of optometry right away.

While the symptoms listed above indicate eye damage caused by UV exposure, many long-term problems caused by UV exposure are symptom-free. To learn about the UV damage your eyes may already have, visit your doctor of optometry for a thorough eye examination.

Can Sunglasses Expire?

Lucky for you, it may be high time for a new pair of shades!

We’re surrounded by things with expiration dates, from the food in our fridge to the moisturizer we put on our face at night. Over time, the lightbulbs in our lamps go out and the paint on our houses fade. But what about your sunglasses? Do they have a shelf life?

Can Sunglasses Expire?

There are two kinds of people in this world: those that buy a new pair of sunglasses every year, maybe even several pairs, and those that find one good pair that they love and try to make them last. If you are part of the second group, you may want to listen up.

A study was recently conducted by researchers at the University of São Paulo in Brazil to see if sunglasses lost their UV-blocking power over time. As it turns out, everyday wear and tear of sunglasses–like throwing them in your bag without a case or accidentally dropping them on the ground–can cause scratches on the lenses that may be gradually diminishing their efficacy.

While this is an interesting finding, there is a lot more research needed to fully understand exactly how long sunglasses can last and what their “expiration date” may be. For now, we recommend that you continue to take good care of your sunglasses while you have them, and don’t hesitate to get a new pair every year or two. Not only will you always be in style, but you can be sure your eyes are properly protected from the sun!

Remember These Tips When Buying Sunglasses

Not all sunglasses are created equal. Some look stylish, but may not provide the same amount of protection as another pair. When you do buy a new pair of shades, you want to make sure they are serving their purpose, which is to protect your eyes from harmful UV rays!

Here are some tips to remember when buying sunglasses:

• Make sure they block 99 to 100 percent of UV light or have “UV absorption up to 400nm” on the label.
• Larger frames and wraparound styles are great at protecting your eyes from many different angles.
• Remember that the color and darkness of the lens doesn’t affect how well it protects you from UV rays. However, darker lenses can be more useful in very bright conditions.

We Have Just What You’re Looking For!

We have a variety of different styles and brands of sunglasses to choose from. Give us a call or visit us online and see for yourself! It would be a pleasure to help you find the perfect pair of shades for your style and personality.

We love to serve you! Thanks for trusting us with your vision health!

How to Keep Your Eyes Healthy

Don't take your eyes for granted. Take these easy steps to keep your peepers healthy.

1. Eat Well

Good eye health starts with the food on your plate. Nutrients like omega-3 fatty acids, lutein, zinc, and vitamins C and E might help ward off age-related vision problems like macular degeneration and cataracts. To get them, fill your plate with:

• Green leafy vegetables like spinach, kale, and collards
• Salmon, tuna, and other oily fish
• Eggs, nuts, beans, and other nonmeat protein sources
• Oranges and other citrus fruits or juices
• Oysters and pork

A well-balanced diet also helps you stay at a healthy weight. That lowers your odds of obesity and related diseases like type 2 diabetes, which is the leading cause of blindness in adults.

2. Quit Smoking

It makes you more likely to get cataracts, damage to your optic nerve, and macular degeneration. If you've tried to kick the habit before only to start again, keep at it. The more times you try to quit, the more likely you are to succeed. Ask your doctor for help.

3. Wear Sunglasses

The right pair of shades will help protect your eyes from the sun's ultraviolet (UV) rays. Too much UV exposure boosts your chances of cataracts and macular degeneration.

Choose a pair that blocks 99% to 100% of UVA and UVB rays. Wraparound lenses help protect your eyes from the side. Polarized lenses reduce glare while you drive.

If you wear contact lenses, some offer UV protection. It's still a good idea to wear sunglasses for an extra layer.

4. Use Safety Eyewear

If you use hazardous or airborne materials on the job or at home, wear safety glasses or protective goggles.

Sports like ice hockey, racquetball, and lacrosse can also lead to eye injury. Wear eye protection. Helmets with protective face masks or sports goggles with polycarbonate lenses will shield your eyes.

5. Look Away From the Computer Screen

Staring at a computer or phone screen for too long can cause:

• Eyestrain
• Blurry vision
• Trouble focusing at a distance
• Dry eyes
• Headaches
• Neck, back, and shoulder pain

To protect your eyes:

• Make sure your glasses or contacts prescription is up to date and good for looking at a computer screen.
• If your eye strain won’t go away, talk to your doctor about computer glasses.
• Move the screen so your eyes are level with the top of the monitor. That lets you look slightly down at the screen.
• Try to avoid glare from windows and lights. Use an anti-glare screen if needed.
• Choose a comfortable, supportive chair. Position it so that your feet are flat on the floor.
• If your eyes are dry, blink more.
• Rest your eyes every 20 minutes. Look 20 feet away for 20 seconds. Get up at least every 2 hours and take a 15-minute break.

For more information or to book an appointment, visit us at www.visionsourcenw.com.

UV damage you can’t see, but impacts your vision

Summer is officially upon us and Canadians across the country are excited to get outside and enjoy the sun. While most Canucks recognize the importance of sunscreen to prevent sunburns and skin cancer, many are unaware that UV light can cause serious eye damage. In fact, overexposure to UV rays has been linked to a variety of eye problems, one of which is cataracts, a condition where the normally clear lens of the eye become cloudy and opaque.

June is Cataract Awareness Month, and with an estimated 3.2 million Canadians living with the eye condition[1], Doctors of Optometry are urging residents to book an annual eye exam with an optometrist and take the necessary precautions to protect your vision from the sun’s harmful rays.

 

What can you do?

• Avoid sources for UV radiation. Don’t stare directly at the sun and be aware of reflections from snow, water, sand and pavement. If you’re a welder, hairdresser, lighting technician, paint and resin worker, or work outdoors, be sure you’re in the know about potential risks and how to avoid UV exposure.
• Protect your peepers. Wear sunglasses that are 100% UV blocking against both UVA and UVB rays, and are close-fitting with a wrap-around style frame to help keep light out. If you wear corrective contact lenses, consider wearing UV-blocking contact lenses for an added layer of UV protection. In addition to cataracts, these steps help protect against:
• Age-related macular degeneration
• Eyelid skin cancer
• Corneal sunburn
• Age spots
• Tissue growths on the surface of the eye
• Stay informed. Get regular eye exams to monitor eye health, maintain good vision and keep up-to-date on the latest in UV protection (Check out the UV Canada smartphone app for up-to-date info on UV radiation in your location).
• 10-4. Keep out of direct sunlight between 10 a.m. to 4 p.m., when the sun’s rays are strongest.
• Children are at high risk. It’s estimated that 50% of lifetime exposure to UV happens before the age of 18. Keep children younger than six months out of direct sunlight, ensure children of all ages wear sunglasses and sun hats when outside and consider using a canopy or umbrella as a sun-shield when at the beach or in the back yard.
• Recognize the symptoms. If you’re experiencing immediate pain, an inflamed cornea, or an aversion to light, see your Doctor of Optometry right away.

Your Doctor of Optometry can make specific recommendations to ensure your eyes are well-protected and to fit you with your perfect pair of sunglasses. Booking a comprehensive eye examwww.visionsourcenw.com can identify early onset of eye-health conditions related to UV that may not have apparent symptoms.

Cataracts

What is a cataract?

When the normally clear lens within your eye becomes cloudy and opaque, it is called a cataract. Cataracts vary from extremely small areas of cloudiness to large opaque areas that cause a noticeable blurring of vision.

Who gets cataracts?

Cataracts are a function of aging and are most often found in people over the age of 60, although they are also occasionally found in younger people, including newborns. If a child is born with a cataract, it is referred to as a congenital cataract.

What causes cataracts?

Cataracts are the result of aging changes that occur within your eyes that cause the lenses to become cloudy. This may be due to advancing age or it may be the result of heredity, an injury or a disease. Excessive exposure to ultraviolet radiation (present in sunlight), cigarette smoke, certain systemic conditions, or the use of certain medications are also risk factors for the development of cataracts. Cataracts usually develop in both eyes, but often at different rates.

Can cataracts be prevented?

Currently, there is no proven method to prevent cataracts from forming. Wearing sunglasses is a tremendous benefit as they protect your lens from harmful UV rays, which can speed up cataract formation. A diet rich in antioxidants (such as Vitamins A, C, E, Zinc Selenium & Magnesium) can also be beneficial.

What are the signs/symptoms of cataracts?

Some indications that a cataract may be forming include blurred or hazy vision that cannot be corrected by changing the glasses prescription, or the feeling of having a film over the eyes that does not go away with blinking. A temporary change in distance and/or near vision may also occur. An increased sensitivity to glare, especially at night may be experienced. Cataracts develop without pain or redness.

How are cataracts diagnosed?

A comprehensive eye examination by a doctor of optometry can determine if you have a cataract forming.

How are cataracts treated?

In the early stages of a cataract, where vision is only minimally affected, your doctor of optometry can sometimes prescribe new lenses for your glasses to give you the sharpest vision possible. When the cataracts start to interfere with your daily activities and glasses cannot improve this vision, your doctor of optometry will refer you to an ophthalmologist (eye surgeon) who may recommend the surgical removal of the cataracts.

When will I need to have cataracts removed?

Cataracts may develop slowly over many years or they may form rapidly in a matter of months. Some cataracts never progress to the point that they need to be removed. When a change in glasses can no longer provide functional vision, and the cataract is starting to interfere with your daily activities, your doctor of optometry will arrange a consultation with a cataract surgeon.

What happens after cataract surgery?

The old cloudy lens is removed and an intraocular lens implant, inserted in your eye at the time of surgery, serves as a new lens. Sometimes the lens implant can give you good enough distance vision that you may not require glasses. Your near vision will still be blurred, so you may need glasses to read. Your doctor of optometry will prescribe new lenses for your glasses about four to six weeks after surgery to maximize your distance and near vision. Before surgery, your doctor of optometry may recommend lens implant options with new “specialized” intraocular lenses designed to minimize your need for glasses following the surgery.

Detecting Underlying Health Conditions

During a comprehensive eye exam, your doctor of optometry does much more than just determine your prescription for eyeglasses or contact lenses. He or she will also check your eyes for common and rare eye diseases, assess how well your eyes work together as a team and look for indicators of many potentially serious health conditions that affect other areas of the body.

Health Conditions Visible in the Eyes

The connection between vision and other systems of the body make routine eye exams an important part of preventative healthcare— regardless of your age or your physical health. Comprehensive eye exams provide optometrists with a close-up look at your blood vessels, the optic nerves, and other complex eye structures, all of which may contain clues to conditions that could pose a serious risk to your health. A number of underlying health conditions can be detected through a comprehensive eye exam, ranging from high blood pressure and diabetes to certain forms of cancer. Other health conditions that may show signs in the eyes include tumours, aneurysms, autoimmune disorders, thyroid disease, sickle cell disease, liver disease, multiple sclerosis, Parkinson’s disease, and other neurological or brain disorders.

High blood pressure

High blood pressure (hypertension) is a medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms, but if left untreated is a major risk factor for life threatening conditions like heart disease, stroke, and heart attack. Because the eye is the only part of the body in which blood vessels can be viewed without invasive techniques, it can be the first place that high blood pressure is detected.

The retina is a tissue layer lining the inside of your eye. This layer transforms light into nerve signals that are then sent to the brain for interpretation into images. When your blood pressure is too high, for a prolonged period, changes to the retina’s blood vessels occur. During an eye exam, your optometrist will look out for damage to the blood vessels in the retina, helping to detect signs of high blood pressure and identify risks for stroke or heart attack.

Diabetes

Like high blood pressure, diabetes can damage the small blood vessels in your retina. If undetected or not controlled effectively, diabetes can impact your vision and put you at risk of other life threatening complications such as heart disease and kidney failure. With as many as one million Canadians living with undiagnosed diabetes, an eye exam can play an important role in early detection of diabetes and assist in effective management of the disease.

Cancer

A comprehensive eye exam can identify unusual structures and growths inside or around the eye, including a rare form of cancer called choroidal melanoma which develops within the cells that make pigmentation in the eye and can be life threatening if it spreads to other parts of the body.

Brain tumours, depending on their location in the brain, can cause loss of peripheral vision, optic nerve changes, abnormal eye movements, double vision, or other changes in vision. A comprehensive eye exam includes tests of peripheral vision and eye muscle function and can often be the first line of detection of a brain tumour.

Skin cancer can also be detected through an eye exam, as lesions called basal cell carcinomas can show up on the eyelid and, in rare occasions, can spread to the brain through the eye. The eye and its surrounding tissues are one of the most common areas of the body where skin cancer is first diagnosed.

Neurological Conditions and Brain Injuries

The optic nerve in the eye is essentially an extension of the brain and carries signals from the retina’s nerve cells to the brain for processing. Neurological conditions that affect nerve cells, such as multiple sclerosis, may affect vision and be detected through an eye exam.

The muscles attached to the eye that are responsible for coordinated eye movements are controlled through nerves that arise directly from the brain. Several neurological conditions, which affect the brain, including Parkinson’s disease and Progressive Supranuclear Palsy, can affect eye movements and even cause double vision.

Mental health conditions and brain injuries, including strokes, may affect the parts of the brain that control eye coordination and tracking. Strokes can also cause peripheral vision loss. Diabetes can cause nerve damage that can result in double vision. A comprehensive eye exam can detect problems with eye movement, and vision training or spectacle (eyeglass) therapy can improve the ability of the eyes to track and work together.