What are the dangers to the eyes?
Depletion of the Ozone Layer has become a serious problem for the health and welfare of the world's populations. Since 1979, there has been a 4% decrease in the level of atmospheric ozone. For each 1% that the atmospheric ozone is decreased, there is a 2% increase in the level of Ultraviolet B (UVB) reaching the earth. Millions of people around the world are unknowingly risking damage to their eyes from UV. Protection from the harmful Ultraviolet radiation is and will become more of an important topic, especially relative to eyewear where this radiation has been proven to cause various eye problems such as cataracts, sunburn to the eyelids, pterygium, skin cancer around the eyes, and macular degeneration (the leading cause of vision loss among older Americans).
ULTRAVIOLET:
invisible part of light, made up of UVC, UVB, UVA. With prolonged exposure to ultraviolet your eye will turn opaque (impenetrable by light).
1.UVC absorbed by the Earth's atmosphere is below 280 nm*.
2.UVB causes cancer and burning of the eye, most damaging is 280-315 nm.
3.UVA closest to visible light, causes cataracts and Pterygium is 300-380 nm.
VISIBLE:
these are the colors we see in nature. In this spectrum protective eyewear attempts to deal with glare or the brightness of the sun. The unprotected eye strains to focus (squints) on blue light causing chromatic aberration and aging of the eye.
1.Exist on earth from approximately 380 to 780 nm.
2.45% of the sun's energy reaches the earth as visible light.
3.Blue Light - difficult for eye to focus, colors may be distorted (400-500nm).
INFRARED:
cannot be seen but can be felt. They are the thermal or heat carrying rays. Infrared radiation's total effect on the eye is still uncertain at this time.
1.Exist on earth from approximately 780 to 1,000 nm.
2.Heat rays can increase retinal temperature making the cornea more sensitive to damage by UV rays. Can cause drying effect of the cornea.
3.IR can be absorbed in the lens by heating the lens. Because the eye has no ability to cool itself, heat contributes to eye fatigue.
GLARE:
is too much light for our eyes to handle comfortably and efficiently.
1.At times our eyes are being subjected to 10 to 12 times more light than they need. When glare reaches these levels, such as on a bright, sunny day on the water or on a ski slope it can be painful.
2.Glare can come directly from a light source or indirectly from reflections.
3.Sunglasses control glare by reducing the level of light to one that is easier on the eyes.
