Reasons Why You Should Protect Your Eyes From Ultraviolet Rays
People usually have some understanding of the damage that continuous and frequent exposure to the sun can have on the skin, but they do not always consider the effects on the eyes. Light contains invisible wavelengths that can also cause eventual damage to the eyes. These waves can be divided into visible and high energy visible (HEV) light that cause ultra violet (UV) damage if you don’t protect your eyes.
While visible light is the portion that gives the perception of colour to the eye, HEV is the upper end of the spectrum in the violet blue band approaching ultraviolet. Excessive exposure to ultraviolet waves can have effects later in life and can lead to macular degeneration.
Ultraviolet light waves are electromagnetic radiation that is found to be stronger in higher altitudes or in open highly reflective environments such as snow, water and sand. These ultraviolet rays can be divided into three types of light, UVA, UVB and UVC. While most people are aware that excessive exposure to ultraviolet rays lead to sunburn, there are other damaging effects to health that may occur, in particular, to the eyes.
UVA (also known as longwave or black light) penetrates the skin and eyes and may cause premature aging. It has also been linked in the short term eyestrain and fatigue.
UVB (also known as medium wave light) is known to cause the most UV damage and is also known to be a factor in retinal damage and the development of cataracts. Ultraviolet B waves are also associated with other problems that can lead to eye disease and possibly blindness.
Ultraviolet waves of the C subtype (also known as shortwave or germicidal light) are not a particular problem for the eyes as they are mostly absorbed by the outer atmosphere before it reaches the earth. UVC radiation is usually found in artificial sources such as mercury arc lamps and germicidal light.
It is important when buying sunglasses to look for those with 99-100% protection against UV damage. The lower amount of protection is most likely when purchasing photochromic lenses that would need a certain amount of ultraviolet waves to operate adequately.
It is not all bad news, of course some exposure is certainly beneficially to health. All that people should understand is that for health purposes, moderation should be considered when you are out in the sun.
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