Which has a larger retinal image size when corrected with spectacles: a spectacle corrected hyperope or a spectacle corrected myope?

Which has a larger retinal image size when corrected with spectacles: a spectacle corrected hyperope or a spectacle corrected myope?

• A. Spectacle Corrected Hyperope
• B. Spectacle Corrected Myope
• C. Uncorrected Hyperope
• D. Uncorrected Myope

Answer: (A)

Spectacle magnification is what changes how large an image appears on the retina when you wear glasses. Plus lenses (used to correct hyperopia) tend to enlarge the retinal image, while minus lenses (used to correct myopia) tend to shrink it. This effect is roughly proportional to the lens power and the distance from the eye to the spectacle (vertex distance): the larger the plus power, the more the image on the retina is magnified; the larger the minus power, the more the image is minified. So a hyperope corrected with spectacles ends up with a larger retinal image than a myope corrected with spectacles. For example, with typical vertex distance, a plus power yields a small but noticeable magnification, whereas an equivalent minus power yields a corresponding minification, making the hyperope’s corrected retinal image larger.

Spectacle magnification is what changes how large an image appears on the retina when you wear glasses. Plus lenses (used to correct hyperopia) tend to enlarge the retinal image, while minus lenses (used to correct myopia) tend to shrink it. This effect is roughly proportional to the lens power and the distance from the eye to the spectacle (vertex distance): the larger the plus power, the more the image on the retina is magnified; the larger the minus power, the more the image is minified. So a hyperope corrected with spectacles ends up with a larger retinal image than a myope corrected with spectacles. For example, with typical vertex distance, a plus power yields a small but noticeable magnification, whereas an equivalent minus power yields a corresponding minification, making the hyperope’s corrected retinal image larger.