Will a patient with Accommodative Excess have a lag or lead of accommodation on MEM?

• A. Lag of Accommodation
• B. Lead of Accommodation
• C. Neutral
• D. Varied

Answer: (B)

MEM tests how the eyes respond at near by comparing the accommodative response to the near-demand. Accommodative excess means the eye is over-working and focusing more than what the target requires. In MEM this shows up as a lead of accommodation: you neutralize the reflex with minus lenses, indicating the patient’s accommodation is greater than the stimulus from the near task.

For example, at a typical near distance the demand is about 2.50 diopters; if the patient’s true response is greater than that, you’d need minus lenses to neutralize the reflex, which is interpreted as a lead of accommodation. A lag would mean under-accommodation and would be neutralized with plus lenses, while neutral means the response matches the demand, and “varied” would imply inconsistency rather than a defined pattern.