Ultraviolet (UV) rays are invisible rays that are part of the energy that comes from the sun. UV rays can burn the eyes, hair, and skin if these parts of the body are not properly protected, or if they undergo too much exposure to the sun. Nevertheless, they are very useful in our ecosystem.
UV rays assist our bodies in making vitamin D, which strengthens bones and teeth and helps our bodies build immunities to such diseases as Rickets and colon cancer. They are also used to treat psoriasis; the rays slow the growth of skin cells, preventing the outbreak of the itchy patches for which psoriasis is known. They have various commercial uses as well, including sterilization and disinfection. Some animals, such as bees, can see in ultraviolet, which helps them to collect pollen from flowers.
In spite of all their positive uses, UV rays remain very harmful for anyone who spends a large amount of time in the sun without proper protection. The most common effect of exposure to them is sunburn. Sunburn causes blood to rush to the affected area as the body tries to cool the burn, and the damaged skin ultimately peels away. In addition to the burning pain on the skin, sunburn can ultimately cause skin cancer.
Skin cancer is often caused by prolonged exposure to ultraviolet light, but it can occur even when there is no evidence of sunburn. Dark skinned people are just as susceptible as those with fair skin to the damage caused by UV rays. Eye damage caused by these rays first shows up as pain or temporary blindness and blurred vision, but over time, cataracts can develop. The UV index measures the intensity of UV radiation and gives people an idea of how long they may remain in the sun before damage is possible. An index of 1-3 means the possibility for UV damage is low, while and index of 8-10 means the possibility is high.
The best way to combat UV rays is with bodily protection. Always wear protective sunglasses and a hat to protect the eyes. A hat will also protect hair from UV damage, as well as the skin on the face and neck.
While the best protection for the skin is long, loose clothing, this is not always practical, so the next best option is a protective sunscreen. There are many types of sunscreen, but they all have a number indicating how protective they are. The higher the number, the more protection they provide. Always use sunscreen, even if you will only be in the sun for a few minutes. Be smart, cover up, use sunscreen and enjoy the sunshine!