This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
[{'content': 'A patient presents to the emergency depament with uniocular diplopia. Examination iwth oblique illunination shows golden crescent while examination with co-axial illumination show a dark crescent line. Which of the following is the most likely diagnosis - \nSelect and explain. \nA. Lenticonus, B. Coloboma, C. Microspherophakia, D. Ectopia lentis', 'role': 'user'}, {'content': "Answer: D \nExplanation: Presence of uniocular diplopia together with finding of golden crescent on oblique illumination (edge of subluxated lens) or black crecent line on coaxial illumination (edge of subluxated lens) suggests a diagnosis of 'subluxation' of the crystalline lens. Ectopic lentis refers to displacement of lens from its normal position (subluxation, dislocation). (Ref: Ophthalmology by khurana 7th/e p.222 & (2005)/e p.24; Clinical Examination in by Mukherjee 2006/e p.166; Neema 6th/e p.285, 286)", 'role': 'assistant'}]