Question

All of the following are seen in Argyll Robertson pupil EXCEPT:

• A. Near reflex normal
• B. Direct light reflex absent
• C. Consensual light reflex normal
• D. Visual acuity normal

Hint:

Light near dissociation kills both light reflexes; the consensual normal claim is the odd one out.

Answer 1

The Correct Option is C

Step 1: Define the sign. The Argyll Robertson pupil is a small, irregular pupil classically associated with neurosyphilis that shows light near dissociation: it does not react to light but constricts normally on accommodation (near effort).
Step 2: Apply to the light reflex. Because the light pathway is interrupted, BOTH the direct and the consensual light reflexes are absent or markedly impaired. So a statement that the consensual light reflex is normal is false.
Step 3: Answer the except. Since option C claims the consensual light reflex is normal, which is incorrect, it is the exception and the answer.
Step 4: Confirm the true statements. The near (accommodation) reflex is preserved, so option A is true. The direct light reflex is absent, so option B is true. Visual acuity is typically normal because the afferent visual pathway and retina are intact, so option D is true.
Step 5: Conclusion. The false statement is that the consensual light reflex is normal, so option 3 is correct.