Scleral contact lenses are a specialty type of contact lenses that are meant to be used in situations where a normal contact lens may not be the best option for vision correction / treatment. Unlike normal contact lenses, they are meant to function for more than just vision correction.
What are the differences between a scleral contact lens and a normal contact lens?
The biggest differences lie in how they rest on your eye. A normal contact lens is designed to rest on your cornea, the transparent part of your eye that covers your pupil and is responsible for a large part of your ability to see clearly. A scleral contact lens rests on your sclera, the white part of your eye that surrounds your iris. Because of that, a scleral contact lens is bigger in diameter than a normal contact lens. They are designed to vault the cornea, avoiding contact with it, and the space is filled with preservative-free solution. Because your eye is essentially "bathed" in the solution, and the way they rest on your eye, it is meant to support and restore a healthy ocular surface. Additionally, just like a normal contact lens, they are designed to correct your vision, including correcting nearsightedness, farsightedness, and astigmatism.
The purpose of scleral lenses are also different from regular contact lenses. While they do correct your vision, they are meant primarily to help with specific conditions of the eye, such as irregular / distorted corneas caused by: keratoconus, irregular astigmatism, corneal dystrophies, etc. They are also a good option for patients who experience dry eye syndrome, have corneal grafts or nerve damage, or are recovering from eye surgeries such as LASIK, cornea transplants, or surgeries needed as a result of an ocular injury.