In retinoscopy with the sleeve up, how is the mirror positioned?

• A. Plane mirror
• B. Concave mirror
• C. Convex mirror
• D. No mirror

Answer: (B)

The mirror type inside the retinoscope determines how the illumination and the reflected image come back to your eye. With the sleeve up, the instrument is set to use a concave mirror. This mirror concentrates the light into a converging beam, so the light reflected from the retina returns in a bright, well-defined reflex that you can view clearly through the eyepiece. This setup makes it easier to judge the direction of movement of the reflex (with or against) and to estimate refractive status at a short working distance. A plane mirror would give a dimmer, less distinct reflex and a different viewing geometry, while a convex mirror would diverge the light and blur the reflex. No mirror would render retinoscopy ineffective.