Choosing the right contacts can be difficult as there are differences in the types of materials used to make each type of lens and how to properly care for your lenses will depend on the type you wear. Almost all contacts can correct hyperopia, myopia or astigmatism so the choice of what type of lens will suit you best should be based on a discussion with your doctor.
The first step in getting contact lenses is a visit to your optometrist or ophthalmologist. In the United States, it is required to have a prescription in order to purchase contacts. During your visit, your eye doctor will lay out what type of lens will work for your vision corrections needs.
The types of lenses can be grouped based on a number of factors including:
- what they are made of
- how long you can wear them before removal
- how often you are required to dispose of them
- design of the lens
There are three types of contact lens materials. The first material is made from Plexiglas or Lucite and are referred to as "hard lenses." These are rarely used today. The most common material for lenses are known as "soft lenses" and are made of plastics containing water to give them a gel-like feel. Gas permeable lenses, or RGP lenses, are made from more rigid plastics that do not contain water which help in cases of high astigmatism or presbyopia.
Each type of contact lens will have a unique recommended wearing time. If your lenses is classified as daily wear, they must be removed at the end of each day before you go to sleep. However, extended wear contacts can be worn overnight for usually no longer than a week.
Disposal frequencies range between daily disposable lenses, which must be discarded after a day of wear, to reusable lenses that can last six months or longer. It is important to dispose of your contact lenses based on their recommended intervals in order to avoid developing pink eye symptoms or other complications such as a corneal ulcer.
Contact lenses are also available with specialized designs to meet specific needs. Toric contacts are used for correcting either nearsightedness or farsightedness in addition to astigmatism. Bifocal contacts have two separate fields on the lens for near and farsightedness, the same way bifocal eyeglasses do.
In certain cases, traditional lenses may not work for everyone. Your eye doctor can create custom contact lenses to fit your required eye shape and refractive error. Sometimes contacts can give you a feeling of dry or uncomfortable eyes. If you feel like your eyes might be dry due to wearing your lenses you should speak with your eye doctor. There are a number of way to deal with contact lenses for dry eyes including specialty lenses or prescription eye drops.
There are a wide variety of color contacts that can help you enhance your natural eye color or change it completely. Special effect lenses, also called theatrical contact lenses are available with customized designs so you can have the eyes of your favorite animal, super hero, or just about anything else you can think of.