Choosing your sunglasses
The ozone layer protects any form of life existing on earth against excessive exposure to ultraviolet sunrays (UVR). The thinning of the ozone layer has increased the UV rays reaching the earth's surface. It is then very important to protect yourself from the dangerous sunlight rays whether you are in a working environment or having fun outside, and this is very easy to do.
The best protection is to stay away from sunlight and wear protective clothing and a wide brim hat. Also, apply a sunscreen of skin protection factor (SPF) 15 or higher to all areas of exposed skin. This applies to adults as well as children, whose skin is more sensitive.
Your eyes also need protection against UV and intense light.
Why wear sunglasses?
A good choice of sunglasses will help your vision by reducing sun glare, improving contrasts, and allow you to better tolerate the sunlight. Sunglasses which reduce blue light will improve the contrasts. Wearing this type of sunglasses increases your safety when driving or when doing sports.
Sunglasses also help prevent eye damage caused by direct sunlight. Those which absorb at least 75 percent of visible light -- most of them being models -- guarantee a sufficient protection against blue light without distorting the vision. If you spend lots of time in a glaring place, in the sea or snow, for example, wearing protective blue light sunglasses is advised. Amber colored lenses block blue light and make objects viewed from far mist more precise (in mountains). However, they do not always reduce sufficiently the sunlight and make it bearable.
Several years ago, studies demonstrated that many brands of sunglasses did not block UV rays well enough. The question then was if people were better without sunglasses. This fear came from the fact that, when protecting the eyes, sunglasses caused pupil dilatation. We then thought that pupil dilatation allowed a greater number of UV rays to penetrate the eyes. It seems today that this fear was groundless. The pupils are just slightly dilated, even when wearing very dark sunglasses. According to research, current sunglasses block a lot more UV rays than necessary to counterbalance the pupil dilatation.
Do not look at the sun, even if you are wearing sunglasses!! In fact, only welding masks of intensity factor 14 can protect. You should never stare at the sun, as 10 to 15 seconds are enough to burn your eyes, which would normally cause permanent blindness.
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