Corneal cross-linking is a treatment for an eye problem called keratoconus.

In this condition, the front part of your eye, called the cornea, thins out and gets weaker over time. This makes it bulge into a cone shape, which can distort your vision and make it hard to see. If the symptoms of keratoconus get severe, you will need a corneal transplant.

In corneal cross-linking, doctors use eyedrop medication and ultraviolet (UV) light from a special machine to make the tissues in your cornea stronger. The goal is to keep the cornea from bulging more.

It’s called “cross-linking” because it adds bonds between the collagen fibers in your eye. They work like support beams to help the cornea stay stable.

Corneal cross-linking is the only treatment that can stop progressive keratoconus from getting worse. And it may help you avoid a corneal transplant, which is major surgery.