This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and refraction, Subject name: Ophthalmology
Shoening of 2 mm of axial lengsth of eye ball causes - 
Select and explain. 
A. 3D myopia, B. 6D myopia, C. 3D hypermetropia, D. 6D hypermetropia
D: 6D hypermetropia
Answer: D: 6D hypermetropia 
Explanation: 1 mm change in axial length leads to ametropia of 3d. For example 1 mm shoenign an axial length causes hypermetropia of 3D. Reference :Khurana 7th edition,page28