What is the normal range for against motion distance in inches during Bell retinoscopy?

What is the normal range for against motion distance in inches during Bell retinoscopy?

• A. 15-18 inches
• B. 17-14 inches
• C. 20-25 cm
• D. 8-12 inches

Answer: (B)

In Bell retinoscopy, the against-motion distance is the distance from the eye to the retinoscope at which the reflex appears to move opposite the retinoscope’s motion. This distance reflects the eye’s refractive status at the near testing distance. For a normal eye tested at Bell’s near-distance, the reflex neutralizes around 14 to 17 inches (about 35 to 43 cm). Distances outside this range can indicate refractive error or accommodation effects beyond what’s expected in a typical near test. Therefore, the normal range is approximately 14–17 inches.

In Bell retinoscopy, the against-motion distance is the distance from the eye to the retinoscope at which the reflex appears to move opposite the retinoscope’s motion. This distance reflects the eye’s refractive status at the near testing distance. For a normal eye tested at Bell’s near-distance, the reflex neutralizes around 14 to 17 inches (about 35 to 43 cm). Distances outside this range can indicate refractive error or accommodation effects beyond what’s expected in a typical near test. Therefore, the normal range is approximately 14–17 inches.