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: Ophthalmology
First change in Visual field seen in Glaucoma 
Select and explain. 
A. Paracentral scotoma, B. Siedel's scotoma, C. Isopter Contraction, D. Arcuate scotoma
C: Isopter Contraction
Answer: C: Isopter Contraction 
Explanation: First change in Visual field seen Glaucoma is Isopter Contraction but is Visually insignigficant.