Contact lenses are normally used as corrective eyewear in place of eyeglasses. Contacts must be prescribed by an ECP (Eye Care Professional) who should first access the visual needs of the patient as well as the individual's eye structure and lubrication capacity. Now I am sharing some information about types of contact lenses.
- Hard Lenses: Made from PMMA, which is plexiglass or Lucite, these lenses are almost never used anymore but may be preferred or required by the patient.
- Soft Lenses: The most commonly prescribed contact lens is these gel-like containing plastics the size of the iris of the eye. More recently, the silicone hydrogel lenses have been introduced and are usually favored by practitioners since they allow more oxygen to pass between the lens and the eye and are less likely to dry out.
- GP or RGP Lenses: These are “oxygen permeable” lenses that are stiff, waterless plastics geared toward patients with presbyopia and a high astigmatism and a smaller than the iris of the eye.
At presently we are wearing mainly two types they are:
- Daily Wear contacts can be worn throughout the day but must be removed and cleaned nightly. Daily wear contact lenses come in different durations of wear time and must be eventually disposed of and replaced with a fresh pair.
- Extended Wear contacts can be safely worn overnight or up to 7 consecutive days without removal. Continuous wear lenses are a type of extended wear that can be worn for up to 30 consecutive nights without removal.
