The principal danger posed by the sun is in the form of ultraviolet radiation, or for short, UV radiation. UV radiation is a component of solar energy, but it can also be given off by artificial sources like welding machines, tanning beds and lasers.
You are probably aware of the danger posed by UV radiation to your skin, but may not realize that exposure to UV radiation can harm your eyes and affect your vision as well.
There are three types of UV radiation. One type, called UV-C, is absorbed by the ozone layer and does not present any threat. That’s not true of the other two types, UV-A and UV-B. More and more scientific evidence is showing that exposure to both UV-A and UV-B can have adverse long- and short-term effects on your eyes and vision.
If your eyes are exposed to excessive amounts of UV radiation over a short period of time, you may experience an effect called photokeratitis. Photokeratitis is like a “sunburn of the eye” and may be painful. It includes symptoms such as red eyes, a foreign body sensation or gritty feeling in the eyes, extreme sensitivity to light and excessive tearing. Fortunately, this is usually temporary and rarely causes permanent damage to the eyes.
Long-term exposure to UV radiation can be more serious. Studies and research have shown that exposure to small amounts of UV radiation over a period of many years increases the risk of developing cataracts and may cause damage to the retina, a nerve-rich lining of the eye that is used for seeing. Additionally, chronic exposure to shorter wavelength visible light (i.e. blue and violet light) may also be harmful to the retina. Damage to the retina is not reversible.
The effects of UV radiation are cumulative. This means the longer your eyes are exposed to UV radiation, the greater the risk of developing such conditions as cataracts or macular degeneration in later life.
Researchers have not yet specifically determined how much exposure to UV radiation will cause how much damage, but a good recommendation is to wear quality sunglasses that offer good protection and a hat or cap with a wide brim whenever you are working outdoors, participating in outdoor sports, taking a walk, running errands or doing anything in the sun.
To provide protection for your eyes, your sunglasses should:
- block out 99 to 100 percent of both UV-A and UV-B radiation;
- screen out 75 to 90 percent of visible light;
- be perfectly matched in color and free of distortion and imperfection; and
Impact resistant lenses are a must for your sunglasses if you participate in potentially eye hazardous work or sports.
If you spend a lot of time outdoors in bright sunlight, wrap-around frames can provide additional protection from the harmful UV radiation.
Don’t forget protection for children and teenagers. They typically spend more time in the sun than adults.
UV Radiation Checklist
- If one or more of the following factors fits you, you could be in a higher risk category for damage to eyes from UV radiation:
- Do you spend a great deal of time outdoors?
- Do you spend time skiing, mountain climbing or at the beach?
- Do you use a sunlamp or tanning parlor?
- Are you a welder, medical technologist or do you work in the graphic arts or in the manufacture of electronic circuit boards?
- Do you take prescription or over-the-counter drugs that can increase your sensitivity to UV radiation (check with your optometrist, pharmacist, or physician)?
- Have you had cataract surgery in one or both eyes?