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
A 16 year old boy complains of pain in the right eye. After refractometry, he was prescribed a +3.5 D sphere lens. The cover test is normal. There is no heterophoria. The diagnosis is - 
Select and explain. 
A. Organic amblyopia, B. Anisometric amblyopia, C. Emmetropic amblyopia, D. Toxic amblyopia
B: Anisometric amblyopia
Answer: B: Anisometric amblyopia 
Explanation: None