By Dr. Dennis Lauck
With summer rapidly approaching most people find themselves yearning for those bright sunny days and clear skies instead of the dreary overcast days so prevalent during winter in the Midwest. The benefits of sunlight which provides us with much needed vitamin D are well documented. However, as beneficial as sunlight may be to a person’s overall health, without taking proper precautions, those bright, sunny summer days can also be very detrimental to eye health.
Damage to the eye occurs from exposure to invisible ultraviolet (UV) light. For most people, the primary source of UV light is the sun. Welding machines, tanning beds, and lasers can also be sources of harmful radiation. The two types of radiation that are harmful are UVA and UVB rays. Short exposure may cause short term effects called photokeratitis which is like a sun burn of the eyes. This painful, temporary condition does not usually cause any permanent damage; however, longer term exposure to UV radiation can cause more serious side effects, such as cataracts, macular degeneration, and skin cancer of the eyelids. Premature aging (wrinkles and dark spots) is often a more visible sign of overexposure to UV radiation. Up to 90% of skin changes thought to be age-related are actually caused by the harmful rays of the sun!
So, how do you protect yourself from these harmful rays from the sun? The first line of defense is to wear high quality sunglasses. Sunglass lenses should block out 99% -100% of UVA and UVB radiation. The lenses should also screen out 75% - 90% of visible light. You should take care to be sure that your sunglass lenses are matched in color, free of distortion, and free of imperfections. Most sunglass lenses are tinted either gray or brown. Occasionally, you may find other tints, such as the green lenses used in the iconic RayBan™ Aviators. Gray lenses reduce light intensity and provide less color distortion. Brown lenses also reduce light intensity and may provide better contrast. For sports or eye-hazardous work, the lenses should be made of polycarbonate or a Trivex material because these materials are more impact resistant.
Some eyeglass frames provide a “wrap around” feature that may provide additional protection. Wide brimmed hats or caps will also help reduce exposure from the sun. Wearing such a hat may also reduce glare and serves to improve visual acuity. UV damage may occur at a young age since teenagers and children tend to spend more time outdoors than adults. So, don’t forget protection for them! Also, don’t forget that damage from UV may occur at any time of the year, not just during the summer months, and even on cloudy days.
There are specialty lenses for sun protection. Photochromic lenses change or darken with exposure to UV radiation. Once you move away from the UV rays (going indoors, for example), the lenses quickly return to clear. These lenses are available in either gray or brown and the material may be polycarbonate, high index, regular plastic, or glass. The big advantage for these lenses is that they eliminate the need for a second pair of sunglasses or those clip-on sunglasses that are hard to find when you misplace them. A major drawback to photochromic lenses, however, is that they do not darken much while driving since the auto glass filters out most of the UV necessary to activate the lenses. Temperature may also affect the darkening process. For instance, very hot weather may stop the lenses from darkening fully; whereas, cold weather can cause the lenses to darken more than normal. These lenses are often referred to as transition lenses because Transition Optical owns the technology for most of the more popular brands. By the way, Photochromic lenses are available in single vision, bifocal, and progressive designs.
Polarized lenses are another option for sunglasses. These lenses reduce glare from the reflections off different surfaces, such as roads and water. Most people have experienced those annoying reflections off windshields or rear windows from other cars while in traffic. When light is reflected off water, for example, it is primarily reflected in a horizontal direction. Instead of the light being scattered in all directions, it is reflected in one direction thus causing an annoying glare. Polarized lenses reduce the glare by filtering the light so that the glare is eliminated. However, LCD displays, such as dashboards, digital screens, and ATMs may be difficult to see when wearing polarized lenses. Occasionally, cell phones and GPS devices are also hard to see. These lenses are available in photochromic. Single vision, bifocal, and progressive lenses can be polarized. Whether you’re around water or engaging in any other outdoor activity where glare may be an issue, your best option may be polarized sunglasses.
Just about any ophthalmic frame can be made into a stylish pair of sunglasses. Some frames work better than others, and there are some excellent companies who deal only in the manufacturing of high quality sunglasses. It is always best to consult with your eye care professional before buying any sunglass. Certain frames and lenses may be more beneficial for an individual’s specific needs.
In short, as you think about buying that sunscreen to protect your body this summer, don’t neglect protection for your eyes!