Electromagnetic radiation and health of exposure. Ultraviolet light, specifically UV-B, has been shown to cause cataracts and there is some evidence that sunglasses worn at an early age can slow its development in later life. Most UV light from the sun is filtered out by the atmosphere and consequently airline pilots often have high rates of cataracts because of the increased levels of UV radiation in the upper atmosphere. It is hypothesized that depletion of the ozone layer and a consequent increase in levels of UV light on the ground may increase future rates of cataracts. Note that the lens filters UV light, so
UV filter offer some protection against lens contamination while minimising the inherent additional distortion. However, in photography, the term "UV filter" can be also misused as a filter that passes UV light while blocking other wavelengths in the light spectrum, in the same way the term "IR filter" is also sometimes misused. The correct names for such filters though, are "UV pass filter" and "IR pass filter". This is a very specialized area in photography. Excessive UV radiation can expose humans to various risks, including skin diseases such as sunburns, photo-aging, and skin cancers. UV radiation can be classified as UVA (320-400