Which factor increases the risk of infections with GP lenses?

• A. Not cleaning the case
• B. Wearing the lenses during sleep
• C. Poor case hygiene and biofilm
• D. Using daily disposable lenses

Answer: (C)

The main risk factor here is the storage case acting as a microbial reservoir. Microorganisms can adhere to the case surface and form a biofilm, a protective layer that makes them harder to eradicate with standard disinfectants. If lenses are stored in a contaminated case, they pick up these microbes and can deliver them to the eye, leading to infections such as keratitis. That’s why keeping the case clean, using fresh disinfecting solution, rinsing and drying the case properly, and replacing the case regularly are the most effective ways to reduce infection risk with gas-permeable lenses. Using daily disposable lenses removes the storage step entirely, which lowers risk, and sleeping in lenses increases risk overall due to reduced corneal oxygen supply and a more conducive environment for microbes, but the direct driver among the choices is poor case hygiene and biofilm.