Disadvantages of using an abrasive surfactant to clean GP lenses?

• A. Increases wear resistance
• B. Improves deposition resistance
• C. Creates small surface scratches, can reduce CT and create minus power
• D. No changes to lens properties

Answer: (C)

A primary idea here is that the surface integrity of gas permeable lenses is crucial for accurate optics. Using an abrasive surfactant introduces hard particles that can grind the lens surface, creating micro-scratches and removing some material. That roughening and thinning of the posterior surface changes how the lens refracts light, which can shift the prescription toward minus power and alter the central thickness. That is why this option describes a real, practical disadvantage. Abrasive cleaners do not improve wear or deposition resistance, and they do cause changes to lens properties, so the other statements don’t fit. The takeaway is to avoid abrasive cleaners for GP lenses and stick to non-abrasive cleaners that preserve surface smoothness.