Q: What are Ultraviolet rays?

Ultraviolet light is the part of the light spectrum with shorter wavelengths than visible light. It is divided into three ranges called UV-A, UV-B and UV-C.  UV-C rays are the most damaging, but are filtered out by the Earth's atmosphere.  UV-B rays have a lower energy level than UV-C rays and are the ones that typically cause sunburns. The Sun Protection Factor or SPF number found on sunscreens refers to the level of protection against UV-B rays. UV-A rays have the lowest energy of the three types, but penetrate deeper into the skin, damaging the cells and causing premature aging.

Q: How do the UV rays affect your eyesight?

UV rays can burn the skin of the eyelid, the conjunctiva, the clear membrane that covers the white part of the eye, and the cornea, just like anywhere else on the body. Exposure also increases the risk of skin cancer.  In addition, UV rays can cause the conjunctiva to thicken over time creating an irregular ocular surface, and eventually can cause the damaged conjunctiva to grow over the cornea.  Inside the eye, UV rays contribute to cataract formation, the natural clouding of the lens over time, and have been implicated in the pathogenesis of macular degeneration.

Q: What are the best ways to protect your eyes?

Wearing sunglasses while outdoors is the most effective protection against UV light.  A wide-brimmed hat can help block some exposure, and some contact lenses offer UV protection, although they only protect the areas physically covered by the contact lens.

Q: What kind of protective sunglasses should be worn?

Look for sunglasses that offer protection against both UV-A and UV-B rays.

Q: How can UV rays affect your skin and what kinds of illness can you develop?

The most immediate effect of UV light is the stimulation of the pigment-producing cells, called melanocytes, causing a suntan to develop.  A suntan is not "healthy," but is rather a protective mechanism that attempts to block deeper penetration of damaging rays.  Overexposure over a short period kills skin cells.  Inflammation follows as dead skin cells are removed, resulting in sunburn.  UV-A light penetrates deeper and irreversibly damages the collagen in the skin, causing the formation of wrinkles and "sunspots."

The cumulative effect of UV damage is skin cancer and can be divided into three major types.  Basal cell carcinomas are the most common and often appear as small sores that won't heal.  While they do not tend to spread to other parts of the body, they usually are much larger in size than they appear. Squamous cell carcinomas are also common and appear as a small raised crusty bump.  If caught early, they are easily treated.  Melanoma is the least common of the three forms, but is also the most deadly, as it can spread to other parts of the body.  In fact, melanoma causes more than 80 percent of skin cancer deaths.

Q: What is the best way to protect your skin from UV rays?

Sunscreen is the most effective protection against UV light.  A higher SPF rating indicates effectiveness at blocking UV-B light.  The active ingredient in sunscreen is also important.  Sunscreens made with Zinc Oxide absorb the largest range of UV-A and UV-B light.

Q: What kind of sun rays are good for you and what do they provide?

Some UV light exposure is essential, as it stimulates Vitamin D production in the body.  UV light is used in medical applications to treat certain skin disorders like psoriasis and in newborns who are jaundiced.

Q: How much sun exposure should you have, and how do you gain exposure safely?

Sun exposure for 10-15 minutes, three times a week at mid-morning or mid-afternoon is sufficient. Avoid being outside unprotected between 11 a.m. and 2 p.m. when the sun is at its highest. This will minimize risk of overexposure.