by Dr. Jenelle Trenchuk-Saik, O.D.
– The sun’s harmful effects on the skin and the need for ultraviolet (UV) skin protection has been well documented. What might not be as well documented is the harmful effects of UV damage on the eyes and the need for sun protection starting in childhood.
Vision experts agree that children are the most susceptible and most vulnerable to eye damage from the sun. There are a few reasons for children’s vulnerability. The first being that children tend to spend more time outside than the average adult. As a result children can receive up to three times the annual UV dose compared to adults. Secondly, the crystalline lens of children transmits more visible and UV radiation to the retina than the adult lens.
UV radiation comes not only from direct sunlight, but also reflected light. Direct sunlight is more intense at higher altitudes and latitudes closer to the equator. Reflected light is a far more important source of eye damage from UV radiation than direct sunlight. Snow, water and sand are major sources of reflected UV light. Much of the UV radiation that reaches the eye is absorbed by its structures.
What damage can be done? Starting with the lids: basal cell carcinoma is the most common malignant tumor of the lid. Other skin cancers can be present as well. The cornea: keratitis or inflammation can occur. The lens: cataracts are the decreased transparency of the lens and can be caused by cumulative hours of solar exposure. During childhood, the lens does not provide any protection due to its clarity. As we age the accumulation of UV damage can yellow the lens forming cataracts which can act as little filters blocking out some UV radiation to the retina. This is why protection is very important in children. The retina: cumulative exposure to UV radiation can contribute to Age Related Macular Degeneration, the leading cause of legal blindness in the U.S.
Not all sunglasses protect against UV rays. There are three major UV radiation categories: UVA, UVB and UVC. UVC rays are less common and are mostly absorbed by the earth’s atmosphere, but when they do make their way through, they are much more damaging to the cornea in particular. As a general rule, if sunglasses say they are UV protecting they are referring to UVA and UVB. If the sunglasses you choose do not say they are UV protecting, please reconsider your choice as they are more damaging than going without. Your pupil with dilate behind the lens allowing even more damaging UV rays through versus the constricted pupil without sun glasses. Polarized sunglasses reduce glare by only allowing light of a certain orientation through and thus improves ocular comfort and vision through reflective surfaces such as water. These lenses are great for people who spend a lot of time on the water or driving.
Vision is one of the most important senses that we as humans have. Protecting your eyes early in childhood and throughout life will help them function, for a lifetime, in high definition!
Dr. Jenelle Trenchuk-Saik is an Optometrist, practicing at the Alberta Sports Vision Institute in Wolf Willow with her husband Dr. Brent Saik since 2009.