What is the main cause of GP lens warpage?

• A. Excessive digital cleaning
• B. Improper storage
• C. Inadequate tear film
• D. Poor material oxygen permeability

Answer: (A)

GP lens warpage happens when the lens is physically deformed by handling. Rigid gas-permeable lenses are stiff, so rubbing them with fingers during cleaning applies bending stress. If this digital cleaning is excessive, the lens can develop micro-bends that persist after cleaning, altering the curvature and, thus, the prescribed power or fit. This makes excessive digital cleaning the most common cause of warpage.

Other factors like storage, tear film quality, or the lens material's oxygen permeability affect comfort and vision in other ways, but they don’t typically distort the lens shape the way repeated, forceful cleaning does.