Sunglasses: Hi-tech or Eye-tech?
Srikanth M, Associate Optometrist, Bausch & Lomb School of Optometry, L V Prasad Eye Institute
Sunglasses are worn both for protection and for making a style statement. So what key pointers should one keep in mind when choosing trendy sunglasses?
What should one follow - the trend or technology?
We provide some useful guidelines to answer the various queries with respect to choosing appropriate sunglasses.
Material: The material of the sunglass depends on the geographic location that dictates the weather pattern, and the individualís preference. If one perspires more or is allergic to metal frames, they should choose acetate based or plastic material frames.
Shapes and sizes: The shapes and sizes are very important while choosing the sunglasses. The shape of the frames should be in contrast to the shape of the face. For instance, a round face would be complemented with rectangular shaped frames. The size of the sunglasses is chosen based on the going trend, sometimes shorter and sometimes bigger. However, technically while choosing sunglass, one should remember that the eyes should be at the centre of the glasses.
Protection from ultra violet (UV) rays: The eyes should be protected from the harmful effect of the UV rays produced naturally from direct sunlight or reflecting off snow, water, roads or from artificial sources. UV rays causeexternal and internal damage to the structures of the eye. Externally it can cause pterygium, pinguecula,photokeratitis and internally it can cause the opacity of the natural lens in the eye, called as cataract.
Tinted, polarized or photochromic: Tinted lenses would just decrease the amount of light through the sunglasses giving a soothing effect and can enhance the optical performance of the wearer.But tinted lenses will not eliminate glare and can also alter color perception of the individual. So be careful in choosing yellow and orange tints. Grey tints are recommended during days of clear skies and bright sunlight, and brown tints enhance the warmth of the ambience and hence recommended on cloudy days.
Polarized lenses are the best when you want to avoid the glare from the smooth horizontal surfaces and can be part of your collection of sunglasses. Photochromics are good for those who have to move often from indoors to outdoors as these lenses change their tint according to the ambient light conditions.
Wraparound style(bend of the sunglasses): Ensure that the sunglasses are curved such that the eyes are completely covered on all sides. It is also important that the sunglasses are not over curved as this may cause discomfort, head ache and nausea.
Anti reflective coat on inner surfac: A good pair of sunglasses will have anti-reflective coating on the inner side of the sunglasses. This is to ensure that the most annoying reflections which are on the inner side are eliminated for the sunglass wearer. These reflections happen if the sunglassesare not curved and sized appropriately for an individual.
Contact lens usage: Contact lens materials though UV protective, will cover only the pupil and not provide protection for the surrounding part of the eye. So, use of sunglasses is recommended for contact lens users too.
Toughness of the sunglasses: Sunglass should be tough and should withstand impact. The lens which is used should be organic (plastic) such that it is shatter proof.
Prescription sunglasses: Sunglasses are not only available without powered lenses, but also can be made according to prescription. Hence, if you wear prescription spectacles, go for prescription sunglasses too in order to enjoy better vision under the sun.