Are Plastic Eyeglasses Lenses Injurious to the Eyes?
A popular misconception in India. Whether the lenses are made from plastic, glass, compound resins or quartz, it matters little as long as they are optically perfect. Optically speaking, moulded plastic lenses are excellent as improved designs, which decrease optical aberrations in the periphery of the lens, can be made, which is not possible with glass lenses. What are the advantages of plastic spectacle lenses over glass lenses? There are specific indications: (a) When the power of a lens is high, especially plus, the glasses become every heavy and slip down the noes. The weight causes a constant ache. Plastics because of their extreme lightness are the answer. (b) Since plastic lenses do not fog due to changes in temperature, a worker who goes in and out of in air-conditioned or refrigerated room would find them extremely useful. (c) For those with low vision, who need a combination of lenses, plastic lenses are the answer. What are the disadvantages of plastic lenses? (a) They scra