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
Amblyopia means 
Select and explain. 
A. Colour blindness, B. Any detion from normal usual function of eye, C. Squint, D. None of the above
B: Any detion from normal usual function of eye
Answer: B: Any detion from normal usual function of eye 
Explanation: B i.e. Any detion from normal usual function of eye