Sunlight reaches us in heat waves called infrared, or invisible rays called ultraviolet (UV). Ultraviolet rays, in small amounts, act as a catalyst in
the manufacturing of vitamin D in our bodies. Although some UV is necessary for our well-being, over exposure can cause premature wrinkling, skin cancer, and photokeratitis, or snowblindness. Research has shown that UV rays damage the DNA in our skin cells, putting us at higher risk for skin cancer, and permanent eye damage.

Our skin is made of an outer layer (epidermis), and an inner layer (dermis) that contain cells which produce melanin, a pigment that absorbs UV light. Tanning happens when the skin pumps out abundant of melanin from overexposure to the sun.

Chances for UV damage increase with altitude and latitude. Higher elevations have a thinner atmosphere, so not only are you closer to these harmful rays, there is less atmosphere blocking them. The same goes for the equator - the closer you are to zero degrees latitude, the stronger the UV's. Water and snow also increase sun exposure by reflecting these harmful rays, penetrating your skin from every angle.

UV rays are divided into two categories: UVA(Aging) and UVB(Burning). Until recently, sunscreens guarded against the UVB rays, but researchers at Duke have clearly found that UVA rays are just as dangerous, causing leathery, sagging skin known as photoaging, as well as cancer, and cataracts. Exposing your eyes extensively to UVB rays can also burn the cornea, which has the ability to regenerate in 7 days. However, without recuperation time, you can permanently cloud, or loose your vision entirely. Even more damaging to the eye are UVA rays that radiate past the cornea straight into the lens, forming sun cataracts from prolonged exposure. Unlike the cornea, the lens cannot regenerate itself, so reversing or halting cataract forming process is impossible.

As for skin, the most dangerous cancer is malignant melanoma, which appears
as a black, blue-black or bleeding mole. Surgical removal of the mole offers
a chance in eliminating its spread, but once melanoma spreads under the skin,
it is essentially incurable. The incidence of melanoma has risen 300 percent
in the last 40 years in this country; 32,000 are diagnosed with it annually,
according to Harrison's Principles of Internal Medicine.
Plan accordingly: avoid the sun from !0 a.m. to 3 p.m. if possible.

There are many ways the outdoor enthusiast can prevent accelerated aging
and skin cancer. Avoiding the sun during the peak hours, 10 a.m. to 3 p.m.,
is one way. Using a quality sunscreen, and dressing appropriately (sun visors,
lightweight clothing, sunglasses) are two other ways to prevent UV damage.
SUN PROTECTION

Apply sunscreen when your skin is cool and dry. This means 15-30 minutes
before you go outside.

Most sun damage occurs within the first 10-20 minutes of exposure. That means
getting that the mail, or chatting with a friend on the porch can put you
at risk if you haven't applied protection before you leave the house. Remember,
the more pale your skin, the less melanin it has for absorbing UV rays, so
doctors recommend applying sunscreen at least 20 minutes before you go outside.
If you are using DEET and sunscreen, apply the sunscreen first for 20 minutes,
then slap on the DEET.

Suncreens absorb UV rays, but can only hold so much radiation at a time.
Reapply sunscreen every 30-60 minutes when exercising and swimming.

Sunscreens work by absorbing the UV rays, preventing them from soaking into
your skin, but they can only hold so many UV rays. The sun then starts counteracting
sunscreen's function by breaking down some of its protective ingredients.
That's why you need to reapply sunscreen regularly: every 30 to 60 minutes.

Your skin tone dictates which SPF (Sun Protection Factor) you'll need.

SPF stands for Sun Protection Factor, which represents an equation for determining
how long it takes protected skin to burn, compared to unprotected skin. In
laymen's terms, if you usually burn in 10 minutes, an SPF of 15 will provide
a 150 minutes of protection. Someone who burns at 25 minutes gets the same
protection with an SPF 10 as a person who burns at 10 minutes gets with a
SPF 25. So, people with fair skin need to reapply more often than people with
darker skin tones.

Most sunscreens only protect against UVB rays that burn the skin.

Most sunscreens protect against UVB rays, which burn the skin, misleading
people into believing that they can stay in the sun longer. Although they
are not burning their skin, people sunning are exposing themselves to the
cancer causing rays UVA for longer periods.INGREDIENTS

Titanium dioxide, and zinc oxide protect against UVA rays.

Since we now know that both UVB and UVA rays are harmful, your sunscreen
should contain protective ingredients for both of the UV rays. Zinc oxide
and titanium dioxide blocks most of the UVA, but aesthetically, this is not
an attractive idea. Fortunately, sunscreen manufactures have recently discovered
a micronized, clear, zinc oxide and titanium dioxide.

Broad Spectrum does not always mean full UVA/UVB protection.

People refer to these new sunscreens as Broad Spectrum, designed to protect
against UVA and UVB rays. However, current labeling laws allow manufacturers
to use the Broad Spectrum sticker as long as it protects against some
UVA rays.

Suncreens are guaranteed for 2 years; less if exposed to extreme temperatures.

These protective chemicals can be altered in extreme heat or freezing cold,
sometimes disrupting their effectiveness. Sunscreens also have a shelf life
of about two years, which is stamped on the bottle, after which they become
unreliable.CLOTHING

Clothing also offers SPF protection.

You can also protect your skin with clothing, but surprisingly, not all outerwear
protects against UV rays. A standard tee shirt, for instance, only offers
an SPF of 6 to 8. There are, however, clothing manufacturers, such as Tarponwear
International and Sun Precautions, that produce clothing with SPF's as high
as 250, backed by many of their own tests.

To date, there are still no federal regulations for SPF ratings in clothing.

Although many manufacturers list SPF ratings on their clothing tags, there
is not yet an accreditation process to regulate these claims. The Federal
Trade Commission (FTC), together with the American Society for Testing and
Materials (ASTM) are currently exploring the many outside influences on fabrics,
such as salt and chlorinated water, stretch, and durability to determine a
standard for clothing in relation to sun protection.

As for protecting your eyes, the best prevention is wearing sunglasses, even
on cloudy days. The key for protection, in low end or expensive glasses, is
an ASNI-280.3-1996 rating (American National Standards Institute's ophthalmic
requirements). This stamp ensures that the sunglasses block 99-100 percent
of UVB rays, and 95 percent of UVA rays. This rating in a pair of wraparound
shades that keep UV rays from seeping in from the sides, is your best source
for eye protection.