plastic spectacle frame

spectacle frame, plastic 

A structure in plastic for enclosing or supporting ophthalmic lenses. Common materials include carbon fibre composite materials, which are a mixture of principally carbon and nylon in different percentages, cellulose acetate, cellulose propionate, nylon, epoxy resin (trade name Optyl), and Perspex and Plexiglas (which are both trade names for acrylic plastics containing mainly polymethyl methacrylate). Most of the plastics used are thermoplastic, i.e. a material which softens with heat and can thus be manipulated to fit the patient's head and to insert and remove the lenses. See frame heater; polymethyl methacrylate.
References in periodicals archive ?
Until recently, in India, a small semi-circular piece cut from the periphery of an old gramophone record used to be glued to the inside of the upper portion of a plastic spectacle frame to lift the drooping upper lid.
Moss also details the making of an improved prop by utilising orthodontic round steel wire, and fixing it to the bridge of a modern plastic spectacle frame to improve cosmesis and give greater movement to the upper lid.
Although plastic spectacle frames are thought to be generally suitable for patients with sensitive skin, cellulose acetate frames can develop a rough, matt surface after prolonged wear and contact with the skin.