Compared to lower powered fundus lenses, higher powered fundus lenses have what effect on magnification?

• A. Lower magnification
• B. Higher magnification
• C. No change in magnification
• D. Magnification depends on working distance

Answer: (A)

Magnification with a fundus lens depends on the lens’s power: higher power lenses actually reduce the size of the retinal image you see, while lower power lenses give you a more magnified view. The reason is tied to the lens’s focal length: as the diopter power increases, the focal length shortens. The retina’s image formed by the lens sits closer to the lens, so when you look through the eye, that image subtends a smaller angle and appears less magnified. In practice, high-power lenses (like those in the higher diopter range) provide a wider field of view but less magnification, whereas lower-power lenses (lower diopters) offer greater magnification of retinal detail.