For large differences in retinal size magnification (RSM), what is a reasonable single prescription adjustment for the eye with the highest magnification?

For large differences in retinal size magnification (RSM), what is a reasonable single prescription adjustment for the eye with the highest magnification?

• A. Prescribe Thinner Lens For Eye With Highest RSM
• B. Prescribe Thicker Lens For Eye With Highest RSM
• C. Prescribe Flatter Lens For Eye With Highest RSM
• D. Prescribe Steeper Lens For Eye With Highest RSM

Answer: (A)

Retinal size magnification from spectacles depends on the lens power and how far the lens sits from the eye; higher power increases magnification. When one eye shows a noticeably larger retinal image than the other, a practical single adjustment is to reduce magnification in that eye by lowering its power. Prescribing a thinner lens achieves this more directly, decreasing the eye’s effective dioptric power and thus the magnification. A thicker lens or a steeper curve would raise power and worsen the disparity, while a flatter lens might reduce power only indirectly. So choosing a thinner lens for the eye with the highest magnification best balances the retinal image sizes.

Retinal size magnification from spectacles depends on the lens power and how far the lens sits from the eye; higher power increases magnification. When one eye shows a noticeably larger retinal image than the other, a practical single adjustment is to reduce magnification in that eye by lowering its power. Prescribing a thinner lens achieves this more directly, decreasing the eye’s effective dioptric power and thus the magnification. A thicker lens or a steeper curve would raise power and worsen the disparity, while a flatter lens might reduce power only indirectly. So choosing a thinner lens for the eye with the highest magnification best balances the retinal image sizes.