There is no firm consensus in the medical community about the causes of Keratoconus. However, we do know that it develops when the collagen protein fibers in the eye weaken. When collagen in the eye weakens, it can cause the cornea to lose its shape. (Think back to your days on a playground when a rubber ball became lopsided with a bulge on one side.)
One cause of this weakness could be due to free radicals in your eyes. Every day, your corneas produce harmful by-products known as free radicals. Antioxidants in your eyes typically get rid of these free radicals, but individuals with Keratoconus don’t produce enough antioxidants to fight off the free radicals. As collagen levels decrease, the corneas lose their strength and start to bulge.
The weakness can also be caused by frequent rubbing of the eyes. There may be a genetic component as well, since those with KC in their family are more likely to also have the condition.