LASIK Facts

Contact lenses also called “contacts” or “lenses” are corrective, cosmetic, or therapeutic lenses usually placed on the cornea of the eye.

Contact lens usually serve the same corrective purpose as conventional spectacle lenses, but are much smaller and almost invisible. Many contact lenses are tinted with a faint blue or green to make them more visible when immersed in cleaning and storage solutions. This tint is also known as “handling tint”. Cosmetic lenses are deliberately colored for altering the appearance of the eye.

Types of contact lenses
Corrective contact lenses – A corrective contact lens is a lens designed to improve vision by neutralizing the refractive defect of the eye. In many people, there is a mismatch between the refractive power of the eye lens and the length of the eye, leading to a refraction error. A contact lens neutralizes this error and re-focus images directly onto the retina instead of before or behind. Conditions correctable with contact lenses include near (or short) sightedness (myopia), far (or long) sightedness (hypermetropia), astigmatism and presbyopia.

Tinted contact lenses – Tinted contact lenses are designed to change the appearance of the eye. This type of contact lens is very popular among young people.

Therapeutic contact lenses - Soft lenses are often used in the treatment and management of non-refractive disorders of the eye. A bandage contact lens protects an injured or diseased cornea from the constant rubbing of blinking eyelids and in some cases eye lashes, thereby allowing it to heal. Contact lenses to deliver drugs to the eye have also been developed.

Complications
Complications due to contact lens wear affect effect a very small percentage of contact lens wearers. Excessive wear of contact lenses, particularly overnight wear, is associated with safety concerns. Hydrogen silicone lenses are the latest technology in lens material and are in many cases suitable for extended or even overnight wear.

Problems associated with contact lens wear may affect the eyelid, the conjunctiva, the various layers of the cornea, and even the tear film that covers the outer surface of the eye.