______________ compares the retinal image size in an uncorrected eye with the retinal image size in a corrected eye.

• A. Spectacle magnification
• B. Image magnification
• C. Retinal magnification
• D. Anamorphic magnification

Answer: (A)

Spectacle magnification is the ratio that describes how the retinal image size changes when you wear corrective lenses compared with not wearing them. It captures how the lens power and viewing geometry—like vertex distance—alter the image the retina receives. When you compare an uncorrected eye to a corrected eye, you’re looking at how much the lenses magnify or minify the retinal image, and that precise comparison is what spectacle magnification quantifies. This concept matters because differences between the two eyes’ magnifications can lead to aniseikonia, affecting binocular vision. The other terms aren’t the standard way to describe this specific comparison: image magnification is a general term, retinal magnification isn’t a common clinical term, and anamorphic magnification refers to unequal magnification in different meridians rather than the overall uncorrected-vs-corrected retinal image size.