The primary contact focal points were made of glass, in 1888. At first, the glass was blown however soon focal points were made by being ground to shape. For the initial fifty years, glass was the main material utilized. The cheap colored contact lenses were slight, at this point reports of injury were uncommon. In 1938 perspex (polymethylmethacrylate, or PMMA) started to supplant glass in contact focal point produces. PMMA focal points were simpler to deliver so the development of glass focal points before long finished. Focal points made of PMMA are called hard focal points. Delicate contact focal points were first delivered in 1961 by Czech compound designer Otto Wichterle utilizing polyhydroxyethylmethacrylate (pHEMA), a material that accomplished long-haul business applications. Focal points made of polyacrylamide were presented in 1971.
Utilizations of scleral focal points
- Clinical purposes
Scleral focal points might be utilized to further develop a vision and decrease …