What is keratoconus?

Keratoconus is an eye condition where the cornea, the clear, dome-shaped “window” at the front of the eye, becomes thinner and distorts into a ‘cone’ shape. This causes blurry vision which usually progressively worsens. The cause is not fully understood, but it's thought that eye rubbing may weaken the structure of the cornea, so that should be avoided. 

In the early stages of keratoconus, glasses and soft contact lenses may help, but as the condition progresses only special rigid contact lenses provide clear vision. A new procedure called collagen cross linking may help to stabilise or reduce progression. If the keratoconus becomes severe enough, a corneal graft (transplant) may be needed, but not everyone gets to this stage. For most people with keratoconus, rigid contact lenses provide decent vision.