Which parameter is primarily used to specify the refractive correction in a GP lens?

Which parameter is primarily used to specify the refractive correction in a GP lens?

• A. Power
• B. Base Curve Radius
• C. OAD
• D. OZD

Answer: (A)

The key factor for refractive correction in a gas-permeable lens is the lens’s optical power, measured in diopters. This is the amount of light bending the lens provides to offset the patient’s refractive error, so selecting the correct power directly determines the sharpness of vision. The back curve radius mainly governs how the lens sits on the eye and its stability, not how much it corrects vision. The overall diameter and the optical zone diameter influence fit, coverage, edge behavior, and centration, but they don’t set the amount of refractive correction. So the power is the parameter that specifies the refractive correction.

The key factor for refractive correction in a gas-permeable lens is the lens’s optical power, measured in diopters. This is the amount of light bending the lens provides to offset the patient’s refractive error, so selecting the correct power directly determines the sharpness of vision. The back curve radius mainly governs how the lens sits on the eye and its stability, not how much it corrects vision. The overall diameter and the optical zone diameter influence fit, coverage, edge behavior, and centration, but they don’t set the amount of refractive correction. So the power is the parameter that specifies the refractive correction.