The diagnosis of keratoconus can be made by a cornea specialist who may see typical findings on a slit-lamp examination. In early stages, these eye findings may not be obvious, and the diagnosis is made by computerised videokeratography only. As corneal collagen cross-linking can prevent the progression of keratoconus, it is important that teenagers with progressive short-sightedness and astigmatism be screened for keratoconus.
There is no way to tell how fast keratoconus will progress but as the disease advances, the cornea will bulge more and the vision will worsen. In very severe cases, a membrane within the cornea may tear resulting in a sudden drop in vision. This is known as corneal hydrops. The cornea swells and this condition may persist for weeks or months, ultimately resolving with a corneal scar.