This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Investigation in ophthalmology and miscellaneous topics, Subject name: Ophthalmology
All of them are true in ocular ischemic syndrome except 
Select and explain. 
A. It occurs when the carotid aery obstruction reaches 90%, B. Dull pain in orbital region which worsens on getting up, C. Delayed recovery of vision following bright light exposure is seen, D. NVI is never seen
D: NVI is never seen
Answer: D: NVI is never seen 
Explanation: Ocular ischaemic syndrome(OIS) results from chronic ocular hypoperfusion secondary to severe( more than 90%) ipsilateral atherosclerotic carotid stenosis.It typically affects older patients and may be associated with diabetes, hypeension, cardio-and cerebrovascular disease. 1. Symptoms are: Gradual loss of vision or sometimes amurosis fugax. Dull orbital pain worsens on getting up as perfusion fuhur decreases. Delayed recovery of vision following bright light exposure is seen known as bright light amurosis fugax. 2. NVI ocurrs in 90% cases in ocular ischemic syndrome.