Risk factors

Factors that may increase your risk of keratitis include:

• Contact lenses. Wearing contact lenses — especially sleeping in the lenses —increases your risk of both infectious and noninfectious keratitis. The risk typically stems from wearing them longer than recommended, improper disinfection or wearing contact lenses while swimming.

  Keratitis is more common in people who use extended-wear contacts, or wear contacts continuously, than in those who use daily wear contacts and take them out at night.

• Reduced immunity. If your immune system is compromised due to disease or medications, you're at higher risk of developing keratitis.
• Corticosteroids. Use of corticosteroid eyedrops to treat an eye disorder can increase your risk of developing infectious keratitis or worsen existing keratitis.
• Eye injury. If one of your corneas has been damaged from an injury in the past, you may be more vulnerable to developing keratitis.