SUNGLASSES are almost a must-have item in this hot weather of ours. We know they protect our eyes from the glare of the sun – in fact, we are advised to use sunglasses to help prevent eye damage. But how do they work exactly? Sunglasses’ premier function is[ihc-hide-content ihc_mb_type=”show” ihc_mb_who=”2,3,5″ ihc_mb_template=”1″ ] to block the sun’s harmful ultraviolet (UV) rays.
There are two types of UV rays: UVA (which cause skin cancer and premature ageing) and UVB (responsible for sunburn). Both types have higher frequencies than the visible light our eyes can perceive.
They damage our eyes the same way they damage our skin, except that even in the shade reflected rays pose a threat to our eyes. Sunglass lenses are made from glass, plastic or polycarbonate, with a special UV-absorbing coating.
A good pair blocks more than 99 per cent of UV radiation from reaching our eyes. Tints and mirror coatings relieve us from squinting, by absorbing or reflecting intense, dazzling light in the visible part of the spectrum (the light we can actually see).
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