What characteristic is attributed to GP lenses that helps provide a stable refractive surface?

What characteristic is attributed to GP lenses that helps provide a stable refractive surface?

• A. They have no water content
• B. They are disposable daily
• C. They offer higher color clarity
• D. They are harder to insert

Answer: (A)

Gas permeable lenses stay rigid on the eye, and their materials have very low water content. That low hydration keeps the lens from deforming with the tear film, so the front surface keeps its exact curvature. With a fixed shape, the refractive surface remains stable, giving consistent, predictable vision as you blink and as tear dynamics change. The other statements don’t address how the optical surface holds its shape—disposability, color clarity, or insertion difficulty don’t determine refractive stability.

Gas permeable lenses stay rigid on the eye, and their materials have very low water content. That low hydration keeps the lens from deforming with the tear film, so the front surface keeps its exact curvature. With a fixed shape, the refractive surface remains stable, giving consistent, predictable vision as you blink and as tear dynamics change. The other statements don’t address how the optical surface holds its shape—disposability, color clarity, or insertion difficulty don’t determine refractive stability.