Sunglasses , shades, goggles   Home
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Sunglasses or  goggles are spectacles or eyeglasses  which have colored or darkened lenses to screen out sunlight and other sources of  strong light. Though initially used to protect the eyes from harmful ultraviolet (UV) radiation and glare from bright lights, they are widely considered a fashion accessory.

Sunglasses are associated with film stars, who initially used it because of the harsh lights used for production of  films. Today , in  addition to protecting the eyes from sunlight , sunglasses are used to hide a persons eyes and face. The person can avoid eye contact while speaking and hide weeping, lack of sleep or eye diseases like conjunctivitis . Doctors recommend wearing sunglasses after cataract operations and similar eye treatments. Blind people may wear sunglasses to avoid making other people uncomfortable.

While selecting sunglasses, it is important to check the specification and ensure that they protect the eyes from all kinds of  UV rays which cause cataracts . Costlier sunglasses may not provide more protection than cheaper models. For sports, unbreakable polycarbonate lenses with nylon frames should be used.

Grey or brown lenses are preferred to avoid or minimize color distortion. Glasses with these lenses are usually worn while driving. People wearing eyeglasses for corrective eye disorders may either get the lenses darkened or use photo chromic lenses. Photo chromic lenses gradually darken when exposed to sunlight and other bright light, and lighten when there is less light. Glass, acrylic, polycarbonate or CR-39 are some of the materials used to make sunglass lenses. Lenses made from glass have the best optical clarity but are heavier.



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