A complete sunglasses lens guide

Photo courtesy of Rebecca Bollwitt on Flickr

Photo courtesy of Rebecca Bollwitt on Flickr

As the days get longer and summer approaches, you might just find yourself spending more time outdoors. Whatever you have planned, from driving on vacation, spending time on the beach or participating in your favorite sport, having the right type of sunglasses can make those activities more enjoyable. Understanding the available lens options will help to enhance the time you spend outside.

Whatever outdoor activity you partake in, utilizing glasses with ultraviolet (UV) protection can protect your eyes from the damaging effects of the sun. UV rays can cause early cataract formation, macular degeneration and other aging effects. All sunglasses lenses should provide protection from UVA and UVB rays.

The right tint color can enhance your outdoor activities by eliminating glare, reducing eyestrain and providing better depth perception. Lens tints may block certain colors while enhancing others. Contrast may be increased with certain tints.

  • Grey lenses provide decreased brightness and glare while maintaining normal color perception; useful very bright conditions.
  • Brown lenses block blue light to improve contrast and depth perception, but change color perception; great for overcast to sunny weather.
  • Yellow lenses are useful in lowlight and hazy conditions and also enhance contrast; useful in indoor as well.
  • Green lenses provide mild increase contrast with maintaining color perception; another good general-purpose lens.
  • Pink and red lenses provide increased contrast but also alter color perception; can be useful in snowy conditions.
  • Polarized lenses are another lens option for your sunglasses. These lenses are available in different tints and decrease glare by use special filter to block glare of flat surfaces such as roads or water; may block certain LCD or LED screens.
  • Photochromatic lenses change colors or darken depending on the amount of UV light. These lenses are useful in variable or changing light conditions. However, these lenses may not fully darken while you are inside a vehicle.
  • Anti-reflective coatings are often used on the back surface of sunglasses to eliminate reflected glare.

Finally, the right lens material is important. Certain glasses may provide the best optical clarity and scratch resistance, but are not impact resistant. Plastic lenses are tintable and more lightweight than glass lenses. Polycarbonate lenses are the lightest weight and most impact resistant making them suitable for sport settings. Regardless of your lens selection, be sure to stay safe and have fun this summer.

~ John Barrón, O.D.
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org

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Tint my world – what different sunglass tints do for my vision

Photo courtesy of Rebecca Bollwitt on Flickr

Photo courtesy of Rebecca Bollwitt on Flickr

Have you ever been shopping for new sunglasses and been asked, “what color lenses would you like?” If you look back over the past century, there have been many different colors of sunglass lenses that were popular. Back in the 1930’s, Ray-ban developed their B-15 brown lens to be used by US Airforce pilots. Followed up by the G-15 with grey-green sunglass lens, standard in the iconic Wayfarer in the 1950’s. In the 80’s, Vuarnet came out with the popular Px 2000 amber lens to increase contrast and the Px 5000 brown lens for extreme conditions of high mountains, glaciers and desert.

Revo – blue, Suncloud – red, what is the best color for your sunglass lenses?

The following is a guide to the benefits of different lens colors:

  • Grey – most common lens color; this tint is considered neutral because it maintains true colors while decreasing light levels. Good for general outdoor activities.
  • Green –works the same in any light condition; they can be used for just about any outdoor activity.
  • Brown and Amber –causes some color distortion, but also increases contrast. These lenses filter out distortion caused by scattered blue light thus are great for activities like tennis, skiing, boating, high-altitude sports, or other sports where distance vision is important. This tint is also great for golf, as it highlights varying contrasts of green on the golf course.
  • Yellow – like amber lenses, some color distortion, but increased contrast. Great for activities in lower light levels especially with changes from light to shadows. These are the lenses to choose when mountain biking, target shooting, skiing, playing tennis, or piloting an aircraft.
  • Pink, Rose and Red –block blue light, thereby improving contrast. Very soothing to the eyes, they provide good visibility on the road. Great for sports like cycling and racing.
  • Blue and Purple – a high contrast lens that reduces glare from visible white light. These lenses are endorsed by the USPTA for tennis professionals and linepersons in the sport because they block the glare from visible white light.
  • Polarization – though not a tint, polarized lenses offer significant glare reduction. Glare caused by light reflected off flat surfaces including roadways, water and snow is blocked by polarized filters, whereas tints can only decrease light intensity. A polarized lens can be combined with nearly any lens color.

No matter what color lenses you choose, the most important feature of your sunglasses is UV protection. Be sure to ask for 100% UV 400 eye protection to decrease the risk of certain eye diseases including macular degeneration, cataracts, and pterygium. According to the American Optometric Association, to provide adequate protection for your eyes, sunglasses should:

  • block out 99 to 100 percent of both UV-A and UV-B radiation;
  • screen out 75 to 90 percent of visible light;
  • be perfectly matched in color and free of distortion and imperfection

~ Steven Sage Hider, OD
California Optometric Association
http://eyehelp.org
http://www.coavision.org

School is out! How to keep your child’s eyes healthy during summer

Photo courtesy of Andrew Eick on Flickr

Photo courtesy of Andrew Eick on Flickr

A few weeks ago we published a blog about how important it is for our children to spend time outdoors to prevent myopia. ‎

Being outdoors is great for helping to prevent nearsightedness and for exercising our eye focusing muscles, but you may wonder what else you need to do to make sure your child’s eyes stay healthy through the summer.

A few things come to mind.  It has become very common practice to never let our children leave the house with out sun protection: Sunblock, hats, UV blocking clothes and bathing suits. But, what is less common is remembering sunglasses for UV protection for the eyes.  Kids playing outdoors in the sun are exposing the lenses of their eyes and their retinas to harmful UV radiation.  Additionally, their lenses are so young that they do not block UV as well as adult lenses thus sending more UV to the retina.  UV damage to the lens and retina can by a cause of early cataracts and Macular Degeneration.  When buying sunglasses for kids, make sure that they are UV blocking and polarized if possible to reduce glare when around water. More information about children and sunglasses can also be found here.

Next, swim goggles are a good idea for the pool to help keep chlorine out of the eyes.  Chlorine can cause redness, burning, and blurry vision as well.  An added bonus would be swim goggles with a little tint or UV protection as well. If your child experiences these symptoms after playing in the pool, ask your eye doctor what eye drops are right to use to help.

Lastly, the use of sports goggles for eye protection during sports activities is also a must for eye injury prevention while playing soccer, baseball and any other outdoor sports.  For more information about preventing eye injury this summer, here is another great resource.

Enjoy your summer, enjoy the outdoors and the sunshine and stay eye healthy and safe!

~Lisa Weiss, OD, FAAO
California Optometric Association
http://eyehelp.org

http://www.coavision.org

 

 

 

 

Sunglasses- not just a style choice, but a vision-saving device

Photo courtesy of Steven Depolo on Flickr

Photo courtesy of Steven Depolo on Flickr

Not just a style choice

What do you think of when you see someone in sunglasses? Among the most common responses I hear from my patients when I ask them about sunglasses is “fashion.” And while your Michael Kors sunglasses can be an excellent fashion accessory, they can also be a tool well suited to add to your arsenal of eye protection.

Sunglasses are protection

The next question I hear when discussing sunglasses with my patients is “protection from what?” Sunglasses can help provide protection from damaging UV rays of the sun, serve as a barrier for ocular allergens to help reduce allergic conjunctivitis in patients who have eye allergies, and protect the surface of your eyes if you are a patient with tear film insufficiency or dry eyes.

Watch out for UV rays

Damaging Ultraviolet (UV) rays from the sun can cause indirect DNA damage and contribute to skin cancer. It can also cause changes to the health and structure of your eyes. UV ray exposure has unfortunately been linked with a higher incidence of macular degeneration, certain forms of cataracts, and pterygiums (those fleshy growths on the white of the eye that can grow to cover your pupil).

UV radiation from the sun comes in three forms- A, B and C. UV C is the most mutagenic, which means it is the most damaging of the three. Fortunately, our planet’s ozone layer absorbs most of this type of radiation so that it never makes it down to us. UV B is the form of radiation from the sun that causes sunburns, and sunscreens that are labelled with SPF numbers describe how well they block UV B. UV A unfortunately also damages the DNA in your skin and eyes. New full-spectrum sunscreens and sunblocks can help protect your skin from both UV A and UV B radiation. Similar to a full-spectrum sunblock, sunglasses with UV A and UV B protection can help prevent your eyes from exposure to 99.9% of UV A and UV B rays. 

Allergy protection

For patients who suffer from seasonal allergies, especially contact lens wearers, wearing a large pair of sunglasses can be an ideal barrier for potential ocular allergens. Whether they are sport sunglasses or the larger fashion sunglasses, having larger lenses and a bit of face wrap, or curves to fit the front of your face, allow sunglasses to block a lot of the pollens, dust and spores that can trigger eye allergies.

Similarly, for patients who suffer from tear film insufficiency or dry eye, having a large barrier in front of the eyes to protect from the elements encountered outdoors can make treatment and management of this eye disease much easier. 

Sunglasses are always going to be seen as a fashion accessory, but try not to forget how beneficial they can be for eye protection. And remember – there is nothing wrong with looking good while taking care of your eyes! 

~Ranjeet S. Bajwa, OD, FAAO
California Optometric Association
http://eyehelp.org
http://www.coavision.org

Hitting the slopes? Be prepared for snow blindness.

Courtesy of kasiat on Flickr.

Courtesy of kasiat on Flickr.

Tis’ the season to go skiing and snowboarding.  Ski resorts all over the state are opening this month.  It is a well-known fact that spending time outdoors is healthy for not only your body, but your eyes too.  So get ready, get set, and go!  But before you swish down the mountain, ask yourself if you have taken the necessary steps in protecting your eyes from developing snow blindness – a specific form of something called Photokeratitis or Ultraviolet Keratitis.

Snow blindness can be thought of as a really bad sunburn of your eyes (cornea and conjunctiva).  It is caused by exposure of your unprotected eyes to natural sunlight that is reflected off of the snow or ice.  With just the right mix of high altitude and freshly packed snow, your eyes may be subjected to as much as 80% of UV radiation damage in a very short period of time.

After exposure to ultraviolet (UV) radiation, the white part of your eyes (conjunctiva) may look extremely red and the clear covering of your eyes (cornea) may take on a glassy appearance.

Overall, your eyes will not be feeling too great.  With every blink, you may experience unrelenting pain, intense tearing, sandy and gritty feeling, eyelid twitching, discomfort with bright lights and a natural tendency to want to blink more rapidly or shut your eyes tight.  Your vision may be reduced to varying degrees.

The best way to prevent snow blindness is to wear UV-blocking sunglasses or goggles that only allow a certain amount of visible light through. Also, remember to don that protective eyewear whether it is a sunny or a gloomy, overcast day – UV rays can reach your eyes under any condition.

Courtesy of tk-link on Flickr

Courtesy of tk-link on Flickr.

In the event that you forget to bring your sunglasses or you lose them on the way down the slopes and sustain subsequent sun damage to your eyes, your friendly optometrist can promptly treat your symptoms and provide comfort and relief.

While snow blindness is a one form of Photokeratitis,  there are also other forms of which you should be aware, including artificial lights from suntanning beds, electric sparks, halogen desk lamps, flood lights, and arc welding (welder’s flash, arc eye, flash burn) just to name a few.  The prevention is the same.  Wear your UV-blocking sunglasses or goggles to not only look stylin’, but to preserve the health of your eyes and sight.

See you on the slopes!

~Judy Tong, OD, FAAO, FAAO
California Optometric Association
http://www.coavision.org

Summer is coming – protect your eyes while having fun in the sun!

Summer is coming

Most of us understand that we need to protect our skin from UV rays to avoid sunburn and potential sun damage and skin cancer.  But, we often overlook the need to protect our eyes from these harmful UV rays as well.  UV damage can increase your risk of cataract, macular degeneration, pterygium (benign growths on the white part of the eye) and also damage the sensitive skin around the eyes.  The following four tips from the American Optometric Association will help you keep you and your family’s eyes healthy all summer and all year long in the sun.

Here’s what you need to know to protect your eyes:

  1. Wear protective eyewear any time your eyes are exposed to UV light, even on cloudy days and during winter months. Glare from snow on the ground can reflect UV into your eyes.
  2. Sunglasses should block out 99-100% of UVA and UVB radiation and screen out 75-90% of visible light.  Polarized lenses is a good way to do this because they can specifically block out the most prominent light rays while maintaining clear vision.
  3. Grey colored lenses are best. They reduce light sensitivity without altering the color of object and provide the most natural color vision without distortion
  4. Don’t forget your kids! They need sunglasses too as they tend to spend more time outdoors than adults do.

One last tip: Don’t forget about a good quality sunglasses  frame. It should be big enough to protect your eyes and the skin around your eyes from the sun.

Use these tips to keep your eyes safe and healthy through all your outdoor activities.  As always, continue to get routine eye health and vision examinations yearly.

Enjoy the summer!

~Lisa M. Weiss, OD, MEd, FAAO