Composite plastic spectacle lens - has front and rear lenses of di:ethylene glycol bis:allyl:carbonate polymer and polycarbonate or polyurethane resin respectively

摘要

The composite plastic spectacle lens consists of a front lens (12) facing towards the object being viewed and a rear lens (13) facing towards the eye and made from a polycarbonate or polyurethane resin by injection moulding. The front lens can be made from a diethyleneglycol bisallylcarbonate polymer by moulding, and can have a multifocal, progressive multifocal or aspherical surface. The rear lens can have a negative power. ADVANTAGE - Greater lens strength with reduced overall and peripheral thickness.