Saturday , 31 July 2021

The types of material used in a contact lens-

There are mainly 5 types of contact lenses which are based on the type of lens material that has been used. The types of lens materials are –

  1. Gas-Permeable (GP)
  2. Hybrid
  3. PMMA
  4. Hydrogel
  5. Silicone Hydrogel

Soft lens-

These are made by gel-like plastics called hydrogels. These are very thin lenses and these were the only lenses which were popular in the early 1970s as they were really comfortable to wear and use.

Silicone hydrogel lens-

These are an advanced type of contact lenses which are soft and more porous than the regular lenses. Silicone hydrogel contact lenses allow more oxygen to flow inside the lens. This allows the oxygen to enter the cornea, which does not harm the eye and keeps it safe by acting as a natural lens. These were mainly introduced in the early 2000s and became a hit in the United States of America.

Gas permeable lens-

These types of contact lenses are also called as GP (Gas Permeable) and RGP (Rigid Gas Permeable). These are rigid contact lenses that feel like PMMA lens but are porous, which means it allows oxygen to pass through the lens. As they are porous and permeable to oxygen, therefore, it is concluded that GP lenses are fitted closer to the eye than the PMMA lens. Hence making it more comfortable and easier to use than the conventional hard contact lenses. These kinds of contact lenses were first introduced in 1978. Generally worn by people who have astigmatism in their eyes. It will take time for your eye to adjust these contact lenses in the beginning but over time you will be comfortable using it.

Hybrid contact lens-

These lenses are designed to provide comfort to the eye while wearing them. These are soft contact lenses which are made of silicone hydrogel lens and combined with crystal-clear optics of GP (Gas permeable) lens. These lenses are considered difficult to fit and also, they are expensive and hence are not used by many people.

PMMA Lens-

These contact lenses are made from a rigid transparent plastic material which is called polymethyl methacrylate (PMMA). This is also used as a substitute for a glass in shatterproof windows. These contact lenses are not porous and thus they do not allow oxygen to pass through the lenses and therefore it can be quite difficult for any normal person to adapt to these kinds of contact lenses. These are old-fashioned lenses which are also called as “hard contact lenses”. These lenses are rarely prescribed to anyone these days.

What should you be doing about contact lenses?

Contact lenses are very delicate as they are frugal and can be broken very easily so they are needed to handle with care. All the contact lenses have to be kept back in the contact lens case, which comes with 2 sections for both the eyes- left as well as the right. Contact lens case can be bought from the chemist easily and you should make sure that you never mix the 2 lenses as they both are different.