This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S., Subject name: Medicine
What is the diagnosis in this 31-year-old woman with gradual bilateral vision loss? 
Select and explain. 
A. Glaucoma, B. Graves' ophthalmopathy, C. Marfan's syndrome, D. Retinitis pigmentosa
C: Marfan's syndrome
Answer: C: Marfan's syndrome 
Explanation: Answer C. Marfan's syndromeThe imaging shows posterior dislocation of the lens in both eyes. The most common cause of bilateral ectopia lentis is Marfan's syndrome, the diagnosis in this case.