The sun and its consequences (1st part)

It is said that sun exposure is vital for the health of our body. Sun is the primary source of vitamin D which helps our body to absorb calcium for stronger and healthier bones. The sun radiates light to the earth; part of that light consists of ultraviolet rays. However, a raise in the UV made sun exposure more dangerous than previous years; causing serious damages mainly to our skin, immune system and eyes. UV is an invisible sun radiation that enters the atmosphere also in cloudy days; even though there is no sun, people should protect their eyes and skin.
You may think that sun does not cause serious injure to your eyes; let me tell you are wrong. According to recent research, only few hours of sun exposure without sunglasses may damage your eye and redden the retina. This can lasts a few days causing constant heating, headaches, and weep. Going deep, a more serious effect is cataracts. They are caused by a long term sun exposure to sun without the appropriate eyes protection. Unfortunately, there is not treatment for cataracts; the only solution is surgery. A cataract is an opacity developed in the crystalline lens of the eye or in its cover. According to experts, the one way to prevent eyes damage due to sun exposure is the use of sunglasses with the proper UV protection.