This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuro-ophthalmology, Subject name: Ophthalmology
Anisocoria in dim light is maximally seen in - 
Select and explain. 
A. 3rd nerve palsy, B. Pharmacological mydriasis, C. Horner syndrome, D. Parasympathetic paralysis
C: Horner syndrome
Answer: C: Horner syndrome 
Explanation: Anisocoria is a condition characterised by the unequal size of the eyes' pupils. Anisocoria which is worsened ( greater asymmetry between the pupils) in the dark suggests the small pupil (which should dilate in dark conditions) is the abnormal pupil. Suggests horner's syndrome or mechanical anisocoria. Anisocoria which is greater in bright light suggests the larger pupil (which should constrict in bright conditions) is the abnormal pupil. Suggests adie tonic pupil oculomotor nerve palsy, damaged iris and pharmocologic dilatation.