While the exact causes of keratoconus are unclear, both genetic and environmental factors are believed to play a role. One of the most significant causes is habitual eye rubbing.
Many keratoconus patients have conditions such as allergic rhinitis, conjunctivitis, or atopic dermatitis, leading them to rub their eyes unconsciously. Symptoms typically begin to appear in individuals between the ages of 10 and 20 and can progress for 20 to 30 years. The condition results in irregular astigmatism, vision loss not correctable with glasses, light sensitivity, and glare.
In severe cases, the disease can affect the inner layers of the cornea, causing corneal oedema, pain, tearing, and scarring. Rapid progression of keratoconus can even lead to blindness in individuals in their 20s.