Prescription Sunglasses: Whatever the prescription, it is important to protect your eyes against excessive ultraviolet (UV) radiation. Protection is needed to avoid reflected light from sand, water & snow or if you spend long periods out of doors. Prescription sunglasses can be made with single-vision, bifocal or varifocal designs to offer the same standard of protection as non-prescription sunglasses.
Photochromic Lenses: Photochromic lenses change their colour according to light conditions. When exposed to sunlight they darken quickly to eliminate glare and to protect the eyes against UV. The lenses generally clear when it is dark.
Many people wear these lenses and find them convenient, as they automatically darken in the sunshine and can avoid the need for you to carry prescription sunglasses. Modern photochromic materials react and fade quickly, suit most prescriptions and are more likely to be lightweight plastic than glass.
Safety Glasses and Sports Goggles: Special lenses and frames incorporating eye protection are available for a variety of safety and recreational uses.