This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuro-Ophthalmology, Subject name: Ophthalmology
Lesion in the optic chiasma causes - 
Select and explain. 
A. Bitemporal hemianopia, B. Upper nasal, C. Lower nasal, D. Homonymous hemianopia
A: Bitemporal hemianopia
Answer: A: Bitemporal hemianopia 
Explanation: Ans. is 'a' i.e., Bitemporal hemianopia Site of lesionVisual field defectOptic nerveBlindnessOptic chiasmaBitemporal hemianopiaOptic tractIncongruent homonymous hemianopiaLateral geniculate bodyHomonymous hemianopiaOptic radiation (Total)Homonymous hemianopia, sometimes with macular sparingOptic radiation lower fibres (temporal lobe)Homonymous upper quadrantanopiaOptic radiation upper fibres (parietal lobe)Homonymous lower quadrantanopiaVisual cortex (anterior occipital cortex)Homonymous hemianopia with macular sparingOccipital cortex tipHomonymous macular defect