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
Following are the causes of painless sudden onset of loss of vision except ? 
Select and explain. 
A. Acute congestive glaucoma, B. Vitreous hemorrhage, C. CRAO, D. Central serous retinopathy
A: Acute congestive glaucoma
Answer: A: Acute congestive glaucoma 
Explanation: Ans. is 'a' i.e., Acute congestive glaucoma Acute congestive glaucoma causes sudden painful loss of vision.