Which magnification values correspond to hyperopes before and after aspheric correction?

• A. 15%, 3%
• B. 20%, 5%
• C. 25%, 6%
• D. 10%, 2%

Answer: (B)

The concept being tested is how correcting farsighted eyes with aspheric lenses changes the size of the retinal image (spectacle magnification). In hyperopes, the plus-power lenses used to correct vision tend to magnify the retinal image more with conventional designs. Switching to an aspheric correction smooths power across the pupil and reduces aberrations, which lowers the overall magnification of the image seen. In typical hyperopes, magnification before aspheric correction is about 20%, and after applying aspheric correction it’s about 5%. The other options describe magnifications that don’t reflect the substantial reduction produced by aspheric designs.