Keratoconus is a condition where the cornea (transparent structure at the front of the eye) in thin the inferior/central region.

Keratoconus does have a genetic component however it is sometimes associated with other conditions such as allergies, infantile eczema, asthma, reduced night vision, and double jointedness. Keratoconus usually becomes apparent between the ages of 10 and 25 years.

The initial symptom of keratoconus is blurred vision, which is caused by astigmatism. At this stage, good vision can generally be obtained with spectacles. As keratoconus progresses, the shape of the cornea becomes irregular and it is not possible to correct the vision with spectacles alone. In such cases, custom made rigid (hard) contact lenses can be used to provide good vision.

Because the cornea continues to change shape, it is important for individuals with keratoconus to have regular eye examinations to ensure that their contact lenses fit correctly. A poorly-fitting contact lens can cause abrasions, scarring and discomfort.