Which description best characterizes Argyll Robertson pupil?

• A. Pupils that react to light but do not accommodate.
• B. Pupils that do not react to light but accommodate.
• C. Pupils that do not react to light and accommodate.
• D. Pupils that dilate in response to light.

Answer: (B)

Light-near dissociation is the key idea. In Argyll Robertson pupils, the bright-light reflex is lost, so the pupils do not constrict when exposed to light, but the near reflex is preserved, so they do constrict when focusing on a near object. This pattern—no response to light but a normal or near-normal accommodation response—is the hallmark. It’s classically seen with neurosyphilis, where the neural pathway for the light reflex (often involving the pretectal area and parasympathetic fibers to the pupil) is disrupted, while the circuitry driving the accommodation-convergence response remains intact. So describing these pupils as not reacting to light but accommodating captures precisely this light-near dissociation.