Brittle cornea syndrome (BCS) is a rare genetic disorder that affects the cornea, the clear outer layer of the eye. It is characterized by thinning of the cornea, which can lead to vision problems, eye pain, and sensitivity to light. In some cases, the cornea can become so thin that it can rupture, leading to vision loss. BCS is caused by mutations in the ZNF469 gene, which is responsible for producing a protein that helps maintain the structure of the cornea. Treatment for BCS typically involves the use of eye drops and/or surgery to strengthen the cornea.