A 50 year old man with a known history of stroke is unable to get out of his house because he can’t find where the door is. He refuses help from his wife and says he is not blind. What is the single most likely defect?

The key is E. Cortical blindness. [Cortical blindness is the total or partial loss of vision in a normal- appearing eye caused by damage to the brain's occipital cortex. Rarely, a patient with acquired cortical blindness may have little or no insight that they have lost vision, a phenomenon known as Anton– Babinski syndrome].