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
Which of the following is a cause of sudden blindness in a quiet eye with a normal media and fundus: September 2009 
Select and explain. 
A. Acute retrobulbar neuritis, B. Vitreous hemorrhage, C. Iridocyclitis, D. All of the above
A: Acute retrobulbar neuritis
Answer: A: Acute retrobulbar neuritis 
Explanation: Ans. A: Acute retrobulbar neuritis Conditions which produce visual loss with a normal fundus: Amblyopia Coical blindness Retrobulbar neuritis Cone-rod dystrophy Chiasmal tumour