Contact lenses are thin discs that when placed over the cornea of the eye serve to act as a substitute for eyeglasses. The conditions that are corrected by contact lenses are the same as the conditions corrected by eyeglasses and include the following:
o Astigmatism (distorted vision)
o Myopia (nearsightedness)
o Hyperopia (farsightedness)
o Presbyopia (need for bifocals)
Just like no two sets of fingerprints are identical, no two pairs of eyes are exactly alike either. Because of this, there are different types of lenses for different types of eyes. Read below to find out which type of contact lens is right for you.
If you are looking for the lowest-cost alternative in prescription contact lenses, you may want to consider PMMA lenses. These were the first contact lenses ever developed, and though they are not the common choice among contact wearers, are still manufactured today. This type of contact lens is known as being rigid and perhaps a bit harsher on the eye. They are made of sturdier material than other types of contact lenses. These lenses are made of PMMA, a type of plastic that is extremely durable. They are not known to be the most comfortable lenses on the market, but are very durable, and easier on the budget than more comfortable options. This is not the best option for people with sensitive or irritable eyes.
Hard Lenses that Breathe
Rigid Gas-permeable contact lenses, also known as are also known as "RGPs" are a somewhat newer version of hard (rigid) lenses made of plastics as well as other materials, including silicone. A key ingredient in this type of lens - fluoropolymers allow oxygen go right through the lens, thus making it "gas-permeable." Some of the benefits of RGP's are that they are better at retaining their shape, thus providing a crisper vision; they keep your eyes moist, and they resist dust and debris. This type of prescription contact lens is ideal for:
o Those whose eyes are overly sensitive to bacteria or are prone to infection
o Those who are prone to suffering from dry eyes
o LASIK surgery candidates
o People who participate in sports
o Users of bifocal eyeglasses and reading glasses
Soft contact lenses are made of thin plastic and water. The water component gives the lenses a soft and bendable consistency. Soft contact lenses also let oxygen through, allowing the eye to breathe. The majority of prescription contact lenses in the U.S. use soft contact lenses. Some of the reasons for this include the fact that they provide greater comfort, are easier than hard lenses to adjust to and can be worn for longer periods of time. Some of the soft lenses on the market include the following.
Extended wear lenses are soft contact lenses made of materials that allow for use during longer periods of time. This type of prescription lens can be worn for 1-4 weeks without removal and cleaning. Though these types of lenses do allow oxygen to pass through and do tend to keep eyes moist, they are likely not the best option for those with sensitivity and irritability issues.
Disposable lenses are designed to be worn for a limited time and then discarded. This type of lens is excellent for those with sensitive or irritable eyes. Although they are generally more expensive than other types of lenses, the fact that they are replaced daily by a new pair deems them a very low infection risk.