A 70-year-old woman presents to your ED with sudden atraumatic loss of vision in her left eye. This happened 2 hours prior to her presentation and is painless. She is assessed by one of your junior doctors who is concerned about a possible vascular cause. She asks you to help her differentiate a retinal vein occlusion from a retinal artery occlusion.

1. Compare and contrast the two conditions by filling in the table below. 10 marks

2. List (2) other causes of painless unilateral vision loss. 2 marks