This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Bilateral inferior dislocation of lens is seen in ? 
Select and explain. 
A. Marfans syndrome, B. Homocystinuria, C. Weil Marchesani syndrome, D. Trauma
B: Homocystinuria
Answer: B: Homocystinuria 
Explanation: Ans. is `b' i.e., Homocystinuria Ectopia lentis Ectopia lentis is defined as displacement or malposition of the crystalline lens of the eye. The lens is considered dislocated (luxated) when it lies completely outside the lens patellar fossa. The lens is described as subluxated when it is paially displaced but contained within the lens space.