The higher the value, the greater the risk of sunburn and the less time it takes for skin damage. When the UV index is 3 or more, the sun is strong enough to damage some skin types, so it is important to take care of and protect your skin, especially if you burn easily. Both UVA and UVB rays are harmful and can cause damage to the skin, eyes, and immune system. Unprotected exposure to UVA and UVB rays damages the DNA of skin cells and causes genetic defects or mutations that can lead to skin cancer and premature aging.
The skin uses sunlight to help make vitamin D, which is important for normal bone formation. The outer layer of the skin has cells that contain the pigment melanin. Melanin protects the skin from the sun's ultraviolet rays. These can burn the skin and reduce its elasticity, causing premature aging. Everyone needs some exposure to the sun to produce vitamin D (which helps absorb calcium for stronger, healthier bones).
However, unprotected exposure to the sun's ultraviolet (UV) rays can damage the skin, eyes, and immune system. There are other contributing factors, such as heredity and environment. But sunburn and excessive exposure to UV light do damage the skin. This damage can result in skin cancer or premature skin aging (photoaging).In the electromagnetic spectrum, UV light has shorter wavelengths than visible light, so the eyes can't see UV rays, but the skin can feel them.
While this natural UV protection can prevent sunburn to some extent, it cannot protect you from all the different types of damage caused by UV light, nor can it prevent skin cancer. This is because the sun's heat doesn't come from ultraviolet light, but from the infrared light of the sun's rays. Only by gradually increasing your exposure to UV rays over a period of two to three weeks and only exposing your skin to moderate UV radiation, can you achieve a long-lasting tan that will thicken the stratum corneum of the skin and provide some protection from the sun.
