Rigid gas permeable (RGP or GP) contact lenses | 合法醫療器材資訊網

Gaspermeablecontactlensesarerigidlensesmadeofdurableplasticsthatallowoxygentopassthroughthelens.TheselensesalsoarecalledGPlenses, ...

Gas permeable contact lenses are rigid lenses made of durable plastics that allow oxygen to pass through the lens. These lenses also are called GP lenses, rigid gas permeable lenses, RGP lenses and oxygen permeable lenses.

GP contact lenses are rigid, but they shouldnt be confused with old-fashioned hard contact lenses, which are now essentially obsolete. Hard contact lenses were made of a type of plastic called polymethyl methacrylate (PMMA)[1]. Before 1971, when soft contact lenses were introduced, just about all contact lenses were made from PMMA, which is also called acrylic or acrylic glass, as well being referred to by the trade names Plexiglas, Lucite, Perspex and others.

PMMA has excellent optical properties and was developed as a lightweight and shatter-resistant alternative to glass for many applications. But it is impermeable to oxygen and other gases, and the clea...