What are contact lenses?Contact Lens is a thin plastic/silicone piece that can be directly put on the surface of your eye to correct refractive errors. They are the best solution for those who do not want to or are not suitable to undergo refractive surgeries likeLasik and do not want to wear eye glasses at all the times.
They come in different materials and features.
Depending upon the amount of time you prefer wearing them, contact lenses can be classified into the following:
1. Daily Disposables – They are to be disposed after single use.
2. Disposables - Can be worn up to one or two weeks.
3. Frequent disposables - The usage may extend up to a month.
4. Reusable - These lenses have longer durability – up to 6 months or more.
1. PMMA lens -
Poly methyl meth acrylate is the material from which PMMA lenses are made. These are hard, clear and plastic lens with optics. Though these types of lenses have a very good optical value, they are non-porous and do not permeate oxygen to the eye surface. Because of this feature, the PMMA lens can cause discomfort to the eye if worn for a longer duration.2. Gas Permeable Lens -
These are also hard lenses, but they are porous enough to allow oxygen to pass through them. These Lens have all the features of PMMA along with the pores.3. Soft Lens -
These lenses are made up of a special type of plastic called hydrogel. This material is soft and gel like. They are more porous than gas permeable lenses and are soft, thus making them easy to wear.4. Silicone Hydrogel lens -
These Lenses are an advanced version of soft lenses. They are more porous and more easily adaptable. These are now the most popular type of contact lenses used. more