MEM retinoscopy is performed under which viewing condition?

• A. Binocular
• B. Monocular
• C. Both
• D. Neither

Answer: (A)

Monocular viewing is used because MEM retinoscopy aims to isolate the reflex of the tested eye without influence from the fellow eye’s accommodation or vergence. By occluding or otherwise preventing binocular view, you ensure that the accommodation state you’re measuring reflects only the tested eye’s refractive status at the chosen working distance. The examiner observes the reflex in that single eye while neutralizing with lenses to estimate the spherical equivalent and any accommodative lag. If both eyes were involved, binocular fusion and convergence could alter the reflex and lead to a biased estimate, so monocular viewing is the appropriate condition.