Conventional or ordinary plastic, introduced in the late 1960's, was the first lightweight plastic lens and provided improved lens comfort as compared to glass lenses. Conventional plastic lenses still have the same unsightly thick edges as glass, but it has good optical qualities. It also provides more impact resistance than glass, but has less than newer lens materials like polycarbonate and polyurethane high index plastic. It does not have the dramatic cosmetic advantages of newer high index lens materials that combine lightweight with thinness.

PROS OF CONVENTIONAL PLASTIC

• lighter and more comfortable than glass
• more impact resistant than glass
• good optical qualities

CONS OF CONVENTIONAL PLASTIC

• easier to scratch than glass
• same unsightly thick edges as glass
• has less impact resistance than polycarbonate, 1.60 or 1.66 high index plastic