Contact
lenses can be categorized as soft conventional hydrogel, rigid gas permeable or
silicone hydrogel contact lenses. A polymer is a chemical chain formed from
linking many smaller molecules.
lenses can be categorized as soft conventional hydrogel, rigid gas permeable or
silicone hydrogel contact lenses. A polymer is a chemical chain formed from
linking many smaller molecules.
Soft Conventional
Hydrogel
Soft conventional hydrogel contact lenses share a
common backbone of the polymer polyHEMA. This polymer serves as the base for
all soft contact lenses, and different brands are formed by injecting differing
amounts of water and other chemicals into the contact lens as it is
manufactured.
common backbone of the polymer polyHEMA. This polymer serves as the base for
all soft contact lenses, and different brands are formed by injecting differing
amounts of water and other chemicals into the contact lens as it is
manufactured.
Rigid Gas Permeable
Rigid gas permeable contact lenses are also known
as hard contact lenses. Rigid gas permeable contact lenses contain differing
amounts of methyl methacrylate, fluorine, silicon and other chemicals to make
them comfortable to wear.
as hard contact lenses. Rigid gas permeable contact lenses contain differing
amounts of methyl methacrylate, fluorine, silicon and other chemicals to make
them comfortable to wear.
Silicone Hydrogel
Other chemicals, such as polydimethylsiloxane, are
also added to improve comfort. Silicone hydrogel contact lenses are also known
as breathable contact lenses. These contact lenses can be worn overnight in
some cases. Silicone rubber is used as the polymer backbone in silicone
hydrogel contact lenses.
also added to improve comfort. Silicone hydrogel contact lenses are also known
as breathable contact lenses. These contact lenses can be worn overnight in
some cases. Silicone rubber is used as the polymer backbone in silicone
hydrogel contact lenses.