Contact Lenses

What is a Contact Lens?

A contact is a thin, curved lens that sits on top of the film of a person’s eye, resting on a layer of tears. Contact or optical lenses improve an individual's vision. Lenses are basically clear, except for a light tint that enables wearers to see the lenses while inserting and removing them. Lenses are made of both hard and soft materials, but soft lenses are substantially more popular.

What Types of Contact Lenses Are Available?

Contact lens are most often used for vision correction, however lenses are also available that allow individuals to chance the look of their eye color, purely for aesthetics. All contact lenses are regulated by the Food and Drug Administration and require a prescription. Contacts can be made from different materials including:

• Hard Lenses = These are constructed of a hard plastic but are pretty much obsolete today.
• GP Lenses = These are fabricated from waterless, rigid plastics, and allow for the flow of oxygen. GP lenses are best for people with astigmatism. They offer sharper vision than soft lenses.
• Soft Lenses = These are fabricated from a gel-like plastic known as a hydrogel and cover the entire cornea. Silicone hydrogel lenses are an advanced, innovative type of soft lens that allows for increased oxygen flow.
  
  

How Long Do Contact Lenses Last?

Even with proper care, contact lenses must be replaced frequently to prevent the build-up of deposits and minimize the risk of contamination. Soft lenses are offered in different versions, according to the duration of time they can safely be worn. These include:

Monthly – Can be used for up to 30 days before being replaced with a new pair. These lenses should also be properly cleaned and stored at the end of the day to prevent the buildup of deposits on the lenses.

Weekly and biweekly - Can be used for up to seven days and 14 days, respectively. These lenses should also be removed, cleaned, and stored at the end of the day.

Daily - Can be used for no longer than 24 hours and needs to be removed and discarded at the end of the day and replaced with a fresh pair the following day.

Gas-permeable lenses, or lenses that allow more oxygen through them, can last a lot longer because they are not as susceptible to deposit accumulation. GP lenses can last 12 months or occasionally longer.

Types of Lenses Based on Condition

1.  Toric Lenses – Designed to correct astigmatism

2.  Spherical Lenses – Designed to treat myopia, hyperopia, and presbyopia.

3. Multi-focal and Bifocal lenses  –  Designed to correct presbyopia

3.  Scleral Lenses –  Specialized lenses made from gas-permeable materials designed to treat keratoconus, dry eye, and post-surgical complications of the cornea

4. Colored Lenses – Designed to change the color of the iris, the colored part of your eye.