This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Argyll-Robeson pupil is seen in: March 2009 
Select and explain. 
A. Homer's syndrome, B. Retrobulbar optic neuritis, C. Diabetes, D. Neurosyphilis
D: Neurosyphilis
Answer: D: Neurosyphilis 
Explanation: Ans. D: Neurosyphilis Light-near dissociation occurs in Argyll-Robeson pupil. It is seen in Teiary Syphilis (Tabes dorsalis, Taboparesis) Pupil constriction on accommodation is either normal or exaggerated whereas pupillary light reaction is sluggish. There is weak or absent constriction to light, constriction not improved after dark adaptation and fails to dilate after painful stimulation elsewhere.