The term keratoconus refers to an eye condition that occurs when the cornea is thinner than normal, and starts to bulge outward in a cone shape. As the cornea changes, it can deflect light as it enters the eye into the retina, and results in distorted vision. If you are dealing with keratoconus, you may have been told that you're not a good candidate for contact lenses. Thanks to new developments in contacts, there are now some options that should work for you.
Gas permeable lenses are made from an oxygen-permeable material that is rigid, which helps them maintain their shape. They will not stretch or move to fit around the cornea, which means they can hold up well and stay in one consistent shape for those who have keratoconus. These types of lenses can help patients eliminate blurry vision that is caused from the cornea becoming misshapen.
The term piggybacking for contact lenses refers to the wearer using two pairs of contact lenses simultaneously. The first pair that is closest to the eye is a softer lens, followed by a more rigid gas permeable lens over top of it. This is a good solution for people who experience discomfort when wearing the rigid, gas permeable lens by itself. When the softer lens is fitted over the eye, it provides a cushion between the eye and the rigid lens, making them much more comfortable to wear.
Scleral Type Lenses
In some cases, keratoconus causes the cornea to bulge so much that it is not possible to fit a gas permeable contact lens over the eye. When the patient blinks, the lens can become dislodged and fall out. Scleral lenses are different because they are fitted onto the white area of the eyes called the sclera. These lenses are larger in diameter and are shaped in an outward fashion, coming out slightly over the cornea. This can provide a much more stable fit for the wearer and can be more comfortable as well. No pressure is placed directly onto the cornea area of the eye, so they are a good choice for keratoconus patients.
Some contact lenses are called hybrid lenses, and they are also larger in diameter. They contain the rigid portion of gas permeable style lenses, but this material only covers the center area of the eye. Outside of the rigid center is a softer, silicone material that can still provide the wearer with better visual clarity while getting a more comfortable fit. If you have been diagnosed with keratoconus, talk to your optometrist—like those at The Eye Center and other locations—about the different options available to you for contact lenses.