Some Basic Facts:       
– 85% of skin damage results from exposure to the sun’s ultraviolet rays.
– 80% of all skin damage occurs before the age of 18. The damage will be apparent twenty years late.
– 70% of sun damage is the result of accumulated intermittent exposures over years such as when driving or walking.
– Sun damage can lead to premature aging, such as rough, saggy, wrinkled and discolored skin.
– Even normal, everyday sun exposure can cause lines and wrinkles.
– More than 90% of all skin cancers occur on parts of the body exposed to the sun.
– How to chose and apply your sunscreen

How the Damage Occurs:         

The sun’s ultraviolet radiation…
– Stimulates skin cells to produce enzymes that destroy collagen, which gives skin its strength and flexibility. The depletion of collagen makes the skin thinner and less elastic, which promotes sagging and wrinkles.
– Damages skin cells that, in turn, increase melanin production. Higher levels of melanin, a dark pigment that gives skin its natural color, promotes the development of freckles and sun spots.
– Slows the growth of new skin cells and the shedding of older ones. This causes skin to appear coarser, flakier, and more sallow, resulting in prematurely aged skin.

Skin Care Tips for Minimizing the Sun’s Harmful Effects:    
– Limit sun exposure to less than three hours a day.
– Avoid the sun altogether when ultraviolet radiation is strongest between 10:00 AM and 4:00 PM.
– Make a broad-spectrum sunscreen (SPF-20 to 30) part of your everyday skin care routine.
– Apply it at least 20 minutes before going into the sun and reapply it every two to three hours including the ears.
– Keep covered. Wear wide-brimmed hats (at least four inches) and sunglasses with UV lenses to minimize wrinkles around the eyes.
– Cover the sensitive neck and hands areas to prevent wrinkles and dark spots.
– Choose a photostable sunscreen that remains effective even after exposure to the heat in your car or your purse.

Source: Web sites of the American Academy of Dermatology and the American Academy of Facial Plastic and Reconstructive Surgery.