We slather on sunscreen and sport our shades during the sunny summer months. But Dr. Francisco Burgos at Katzen Eye Group says we should also be wearing sunglasses in the winter. The practice's director of refractive surgery services and comprehensive eye care says ultraviolet light can damage eyes at any time of the year.
How can UV rays damage the eyes?
UV light is electromagnetic radiation that is not visible to the human eye. There are several different types of UV light. Some are more common than others, namely UVA, UVB and UVC. A common side effect of UV radiation on a fair-skinned individual is known as sunburn. UV light can also cause damage to the eye's cornea, lens and retina. Ongoing exposure to UV light can accelerate the aging process of the eye and the tissue around the eye. Conditions like cataracts, macular degeneration, pterygium (noncancerous growth in the clear, thin tissue of the eye), pingueculae, and possible blindness can be linked to ultraviolet light exposure. UV exposure to the cornea can also cause a photokeratitis, commonly known as a "welder's flash" and "snow blindness."
Why are UV rays just as bad in the summer as the winter?
UV rays, specifically UVA, are equally intense during all daylight hours throughout the year. Air temperature does not affect the intensity of ultraviolet radiation. ¿
How much exposure does there need to be for damage to occur?
The energy in ultraviolet rays is stronger than infrared and visible light, causing changes in the eye's molecular structure. This is especially dangerous for living organisms as it can lead to cell damage or actual changes in the genetic code. An inflammatory response of the cornea can occur in as little as eight to 24 hours after exposure to significant UV radiation in individuals who didn't use sun protection. This is more common in ski areas or beach areas like in the Caribbean. Other form of UV radiation ocular damage, known as solar maculopathy or sungazing, can occur in as little as 20 seconds or shorter, depending on the way the sunlight was transmitted. Ocular damage can occur over a longer period of time. Conditions like cataracts, pingueculae and pterygium develop slowly over time.
How can people protect their eyes?
Sunglasses and hats are one the most common ways to protect the eyes from UV radiation. Even in the winter months, individuals should wear sunglasses for protection that are clearly labeled as offering UV protection. Skiers at higher altitudes, boaters and beachgoers are at higher risk for damage.
The landmark study on how UV radiation affects the eyes was done right in our area amongst Chesapeake Bay watermen. It was found that those watermen who wore sunglasses had a lower incidence of cataract development. Those who wore hats with wide brims also had a lower incidence and those who wore BOTH sunglasses and hats with brims had the lowest incidence of cataracts. This study demonstrated how important protection from UV light is to minimizing the risk of cataract development.
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Photokeratitis is commonly treated with heavy lubrication, topical corticosteroids, antibiotics and avoidance or limited exposure to sunlight until the condition resolves. When cataracts become significant enough to affect normal day-to-day activities, they can be surgically removed, and in most instances, an intraocular lens can be implanted in order to restore visual function. Likewise, a pterygium may require surgical removal if it becomes clinically significant resulting in vision changes. A pingueculae normally requires more palliative treatment and rarely requires surgical intervention; lubrication and sun protection are commonly used.
Can too much exposure cause blindness?
While some forms of damage from UV exposure are correctable and treatable, there are other forms that can lead to permanent damage and blindness. Solar maculopathy is not reversible and its effects are similar to those of age-related macular degeneration.