There are special types of lenses used for different eye conditions. Below is a list of the most common eye conditions that require specialty lenses.
Keratoconus - This condition occurs when there is thinning of the cornea in an area that creates a cone shaped bulge. There are special types of rigid lenses available to treat keratoconus that help vault over the cone to correct vision.
Pellucid Marginal Degeneration - This is another condition that causes thinning of the cornea. Larger diameter RGP lenses can be used to help correct vision.
Post-surgical corneas - Those who have had a surgery on their cornea may have an irregular surface that causes blur that cannot be fully corrected with glasses. Sometimes the only way to fix this blur is to wear a special lens designed to vault over the irregular cornea. The tears fill in the gap between the lens and the front surface of the eye, which helps to correct vision.
Post-Lasik corneas - Lasik surgery tends to flatten the front of the eye, which helps to correct vision in those with nearsighted eyes (which are too long). Sometimes after Lasik, the prescription can change, which causes the person to need glasses or contact lenses again. Many times due to the new shape of the front of the eye, these people cannot wear regular contact lenses. They need special contact lenses that match the shape of their eyes. These lenses are called Reverse Geometry Lenses.
Bandage Lenses - Bandage lenses are used just like the name implies, as a bandage over a damaged eye. These lenses are fit after a foreign body is removed from the eye and there is a significant wound left behind. Previously, the eye would have to be patched shut for a few days to allow the eye to heal. Now you can use a bandage contact lens, which has several advantages over the old method of pressure patching. One obvious advantage is you can see out of the eye because it is not patched. Another advantage is that oxygen gets to the eye to promote healing, and you can instill antibiotic eye drops right over the bandage lens to treat the area. It’s a lot like using antibiotic ointment and a band-aid for a cut on your skin.
Painted Iris Lenses - These lenses are used for individuals who may have a malformation of their pupil or iris. The painted iris lens can match the color of their other eye. These lenses are also used for those with severe corneal scarring. When the cornea is scarred so much that it can affect someone’s appearance, a painted iris lens is a good choice to take the focus away from that eye for cosmetic purposes.