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 most common cause of myopia is – 
Select and explain. 
A. A–P diameter is increased, B. The thickness of lens is increased, C. The viscosity of aqueous humour is increased, D. The viscosity of vitreous humour is increased
A: A–P diameter is increased
Answer: A: A–P diameter is increased 
Explanation: A most common type of myopia and hypermetropia are axial, i.e. in myopia axial length of eyeball increases and in hypermetropia, it decreases.