Human eye occupies less than 2% of whole body surface area, but still is the sole organ that enables penetration of visible light into the body. It’s imperative to protect and prevent our eyes from several adverse factors that may risk our vision. One such baneful problem is the impact of UV exposure.
The sun supports life on our planet, but its life-giving rays also sustain threats on us. The primary danger is in the kind of ultraviolet (UV) radiation it emits. However, artificial resources, such as welding machines and tanning beds, are also capable of generating UV radiation. Most people are aware of how harmful UV radiation can be for their skin. However, many may not realize that UV radiation may harm their eyes as well.
UV radiation is categorized into three varieties; UV-A, B, and C. Ozone layer in the atmosphere absorbs UV-C rays and is, therefore, less harmful. However, UV-A and UV-B radiation may have long- and short-term negative consequences on your eyes and eyesight. The A type UV rays are responsible for damaging central vision and B type damage the lens and cornea on the front of our eyes.
If your eyes are continuously exposed to UV radiation over a short time period, you will probably experience photokeratitis. Similar to a “sunburn of the eye,” photokeratitis is also painful. Its symptoms include red eyes, a foreign body sensation or harsh feeling in the eyes, extreme sensitivity to light and excessive tearing. Luckily, these symptoms are usually temporary and rarely cause permanent damage to the eyes.
Photokeratitis & Photoconjunctivitis
Photokeratitis is an inflammation of the retina, while photoconjunctivitis refers to an inflammation of the conjunctiva, the membrane that lines the interior of the eye socket and eyelids. These inflammatory responses can be compared to sunburn of extremely delicate skin-like cells of the eyeball and eyelid (they generally appear in a few hours of exposure). Photokeratitis and photoconjunctivitis can be quite painful, but they can be reversible and don’t seem to cause any long-term harm to the eye or eyesight.
An extreme form of photokeratitis is snow blindness. It occasionally happens with hikers, climbers, and skiers, who experience intense UV levels due to high elevation conditions and quite a powerful sunlight reflection — fresh snow can reflect up to 80 percent of incident UV radiation. These extreme UV rays sustain an ability to kill the outer cells of the eyeball resulting in blindness. As the dead cells shed away, snow blindness can be a painful condition to go through. However, new cells grow swiftly, which helps in regaining the vision.
More the eyes are exposed to solar radiation, the higher the chance of developing cataracts or macular degeneration later in life. It’s not clear how much exposure to solar power will cause damage. Thus, once you are firm of spending some time outdoors, wear quality sunglasses that provide UV protection and a hat or cap with a wide brim. Also, certain contact lenses may provide additional UV protection.
