SUNGLASSES are popularly called shades. Most of us wear it as a fashion accessory, without knowing its primary function. On a sunny day, we wear sunglasses to protect ourselves from excessive sunlight, however, what most people fail to realise is that light from the sun is made up of visible and invisible components. There is invisible light called Ultraviolet [UV] rays which have high energy. In small doses, UV rays boost vitamin D but too much exposure can cause problems like eye damage, skin cancer, sunburn. This is because the ultraviolet radiation is harmful to us. They can also be worn to discourage eye contact, hide one’s identity[commonly among criminals], to look cool or hide one’s emotions.
When buying glasses, you have to consider
- Fit: a good pair of sunglasses should fit snugly on your head without being too tight or uncomfortable.
- UV: This is the major reason why sunglasses were made. Now, it’s up to you to decide whether you will invest in a pair that has a UV filter, protects your eyes from excessive exposure to the visible and invisible components of light and filters harmful radiation. It’s common for children to wear them around. Even astronauts need them most because of the harmful UV radiation from the sun.
- Tint: the tint of your sunglasses depends on your environment. For instance, at the beach people wear them to protect their eyes from excessive sunlight because it is too bright or cloudy and from dust particles from the sand. Each lens filters light differently, for instance, grey-tinted lenses reduce brightness without colour distortion, making them perfect for driving. Amber and brown lenses reduce blue light and glare while dark lenses only look cooler, they don’t necessarily protect better. The colour of the glass isn’t an indication of its filtering ability. Have it in mind that a good pair should block 75-90% of visible light.
- Shape: pick a good pair that fits your facial features.
- Material: most of them are made out of plastic, especially the lenses. However, the frames are generally made of plastic, nylon, metal or sometimes wood. Also, the brand name doesn’t really matter but a cheap pair might not have a UV filter.
- Photochromic lenses: if you normally wear eyeglasses, it isw a smart move to get one because they perform two functions at once; correcting your eyesight and protecting your eyes from the suns UV rays when outdoors. Thus, you might not need to get a separate pair of prescribed glasses. Photochromic lenses darken automatically in sunlight.