A. Keratoconus is a disease of increasing near-sightedness (myopia) and astigmatism (irregular and steep corneal shape) that is due to weakening of the cornea. Over time, the weakened cornea can take on a conical shape, giving this disease its name. This process typically begins in adolescence or young adulthood. Many patients are unaware that they have the disease, but find that their vision keeps worsening and that they continually need stronger and stronger glasses, or even hard contact lenses to see well. Many experience difficulty with glare and night vision. Eye rubbing is often associated with this condition. If you are someone who rubs your eyes a lot and has increasing astigmatism, you should be examined to determine if you have this disease. While it can run in families, most patients do not have family members with this condition. To determine if you have this disorder a corneal topography, or surface map, is needed to examine the shape of the cornea. With such mapping, the diagnosis can definitively be made by your ophthalmologist.