The cornea has two functions:
- To protect the eye by forming the barrier between the eye and the outside world;
- To allow light to pass into the eye. The curve of the cornea acts like a lens in this process.
Sometimes there is an irregularity in the cornea. This can be due to an eye disease such as keratoconus, but the most common reason is damage from a sharp object, fireworks or an infection, for example.
When the cornea is deformed or damaged (irregular), traditional contact lenses and eyeglasses are often unable to improve visual acuity. A scleral lens is larger and goes over the cornea. It rests on the sclera, or white of the eye. The cornea is protected in a bed of moisture. This provides great comfort and optimal vision.
It’s not always a refractive defect that causes you to see less sharply. Sometimes there’s something else going on.
Refractive surgery is a collective term for surgical procedures on the eye to permanently correct refractive defects.
Nearsightedness, also known as myopia, is an eye defect in which you have trouble seeing sharply in the distance.