HEALTH & MEDICINE :: AUGUST/SEPTEMBER 2008
Some Contact Lenses Can Protect Against Exposure to Ultraviolet Rays
The damaging ultraviolet rays from the sun dermatologically have been reported for over three decades. However, less is known about the potential ocular risks with respect to UV light. Modern research has linked ultraviolet light to premature growth of cataracts, a higher susceptibility to macular degeneration, photokeratitis (“snow-blindness” or “welder’s flash”) and some ocular melanomas. Although our eyes do provide some natural protection from the sun’s ultraviolet rays, overexposure has the potential for dramatically damaging vision. Even more alarming is the fact that the greatest percentage of ocular damage from UV rays tends to occur before the age of thirty.
Parents should be aware that children and younger adults tend to spend a greater amount of time outside and are more exposed to the sun’s radiation than most working adults. Also at greater risk are persons with occupations that take them outside for a large portion of the day, such as farmers, construction workers and commercial fishermen. Recreational activities like boating, snow-skiing and golfing can also intensify one’s exposure to ultraviolet, since the damaging rays not only come from above, but also bounce off of the ground or water and travel from below. In addition, persons who have resided for several years in the southern United States or in areas closer to the equator have shown a higher tendency for earlier ocular damage from the sun.
The obvious solution to filtering out UV rays is to wear the proper sunglass protect ion. Consumers should look for larger lenses and preferably closer-fitting frames to protect the eyes from light entering from the sides and below. Also, choose no less than 99% to 100% protection from both UVA and UVB rays.
Many people erroneously think that the darker the lens, the better the protection. While darker lenses do provide better filtration of bright light and glare, they really have no affect on the invisible ultraviolet light. A clear ultraviolet coating is placed on most sunglasses, but not all. This same coating can be added to any clear spectacle lenses that are used for every day wear, not just outdoor activities. These coatings are strongly recommended for all glasses, specific for the sun or not.
Unfortunately, not everyone who should wear sunglasses or even prescription glasses of some kind chooses to wear them. Persons with higher prescriptions which tend to correct with thicker lenses may find them uncomfortable, heavy or cosmetically displeasing. These patients usually wear their contact lenses a greater portion of the day or exclusively. Since most contact lenses do not provide glare protection or ultraviolet protection, it is even more important to also have a pair of highly UV protected sunglasses.
Recently however, more contact lens manufacturers have jumped on the bandwagon in realizing the potential dangers of UV radiation to the eyes. Vistakon has added UV blocker chemical to their entire line, and other contact lens companies like Cibavision and Coopervision have promoted certain contact lenses in their lines specific for UV protection.
The Precision UV contact lens from Cibavision was one of the first lenses to address this issue and is still a popular lens for outdoor enthusiasts. It is a twoweek disposable, high-water content lens with prescription suitable for even the higher amounts of near and farsightedness. Its UV protection is 90%, not 100%, providing good blockage of rays for times sunglasses are not appropriate.
Coopervision boasts its Biomedics 55 UV lens, also a two-week disposable. Although it comes under several different names, the ocufilcon material has a track record of fairly reliable comfort and optic. Its UV blockage is around 90-95%, and still provides adequate oxygenation for corneal health. For patients with astigmatism, the Biomedics 55 Toric also comes with the same level of UV protection.
Vistakon, Johnson & Johnson’s vision care division, has added UV blockers to all of their Acuvue family of lenses. The most impressive regarding UV protection are the Acuvue Oasys and the Oasys for Astigmatism which both provide 96% filtration of UVA rays and 99% of UVB. These lenses are also promoted to be one of the highest in oxygenation and patient comfort.
Although ultraviolet protected contact lenses alone do not completely block all of the damaging ultraviolet radiation to which people are exposed, it is reassuring have the technology available, especially during rain, fog or times of day where decreased sunlight make sunglasses a less desirable choice. Used in conjunction with proper UV blocking sunglasses, these types of contacts provide the best assurance for decreasing one’s risk of ocular damage.
Dr. Stewart is part of a thirteen-physician team at Delaware Ophthalmology Consultants. For more information about this article or to schedule an appointment, call 302- 479-EYES (3937) or visit www.delawareeyes.com. Delaware Ophthalmology Consultants has two convenient offices in Wilmington and a third in Middletown. Each location offers full-service optical centers featur ing af fordable, fashionable frame designs and the latest in lens technology.
