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
The following ocular structure is not derived from surface ectoderm – 
Select and explain. 
A. Crystalline lens, B. Sclera, C. Corneal epithelium, D. Epithelium of lacrimal glands
B: Sclera
Answer: B: Sclera 
Explanation: Sclera is derived from mesoderm.
Crystalline lens, corneal epithelium and lacrimal gland are derived from surface ectoderm.