On a direct ophthalmoscope, higher numbers indicate what?

On a direct ophthalmoscope, higher numbers indicate what?

• A. More superficial
• B. Deeper
• C. Retina
• D. Color

Answer: (A)

The numbers on a direct ophthalmoscope are lens powers (diopters) used to focus the retina at different depths. Higher numbers mean stronger converging power, which moves the focal plane forward toward the front of the eye. That makes superficial retinal structures—the ones closer to the inner surface—come into sharp focus more easily. If you want to bring deeper retinal layers into focus, you would use lower diopter settings, since those place the focal plane deeper. The choice reflects depth of focus, not color or simply “seeing more retina.”

The numbers on a direct ophthalmoscope are lens powers (diopters) used to focus the retina at different depths. Higher numbers mean stronger converging power, which moves the focal plane forward toward the front of the eye. That makes superficial retinal structures—the ones closer to the inner surface—come into sharp focus more easily. If you want to bring deeper retinal layers into focus, you would use lower diopter settings, since those place the focal plane deeper. The choice reflects depth of focus, not color or simply “seeing more retina.”