Understand Three Types of Lens Material In Prescription Eyewear14/09/2021
Lenses for eyewear are made of three basic materials – Glass, Plastic and Polycarbonate. Each one of these materials have very different qualities, and it is important that Opticians have full knowledge of each material and when to offer each specific type to a patron.
Glass lenses are much heavier than both plastic and polycarbonate, however, they may provide better quality vision overall and are more scratch resistant than plastic lenses. When it comes to cost, glass lenses are more expensive and take longer to manufacture.
Plastic lenses are standard lenses (CR-39) that don’t come with any form of protection from UV light or glare, nor are they shatter resistant. Each time a prescription is ground into plastic lenses, it is necessary to have the laboratory add extra protections or features onto the lenses for the patron such as UV protection and tint.
Polycarbonate lenses, although a type of plastic, are a thinner, more light weight lens than the regular CR-39 plastic lenses. Polycarbonate is also automatically impact/shatter resistant with built in UV protection which is best for the eyes.
Polycarbonate lenses can be used in more varieties of frames in comparison to glass and plastic and look wonderful, such as with rimless or semi-rimless frames. Where a standard plastic lens may chip on the edge of a rimless or semi-rimless, a polycarbonate lens has far less a chance of doing so due to its built in impact/shatter resistance.