People enjoy the sun. Some have even worshiped it. Sunlight is essential to many living things. But sunlight also has a dangerous side. It can harm your skin and even your eyes. The good news is you can take some simple steps to protect your body from sun damage and still enjoy the sun’s healthful effects.
Our bodies were built to make good use of the sun. Sunlight helps keep our sleeping patterns on track so we can stay awake by day and sleep soundly at night. Getting too little sun, especially in winter months, can leave some people prone to a form of depression known as seasonal affective disorder. Sunlight also helps our skin make vitamin D, which is needed for normal bone function and health. Yet sunlight can also cause damage.
Sunlight travels to Earth as a mixture of both visible and invisible rays, or waves. Long waves, like radio waves, are harmless to people. But shorter waves, like ultraviolet (UV) light, can cause problems. The longest of these UV rays that reach the Earth’s surface are called UVA rays. The shorter ones are called UVB rays.
Too much exposure to UVB rays can lead to sunburn. UVA rays can travel more deeply into the skin than UVB rays, but both can affect your skin’s health. When UV rays enter skin cells, they upset delicate processes that affect the skin’s growth and appearance.
Over time, exposure to these rays can make the skin less elastic. Skin may even become thickened and leathery, wrinkled, or thinned like tissue paper. “The more sun exposure you have, the earlier your skin ages,” says Dr. Barnett S. Kramer, a cancer prevention expert at NIH.