The most common cause of myopia is -
A-P diameter is increased
The thickness of lens is increased
The viscosity of squous humour is increased
The viscisity of vitous humour is increased
Axial type of simple myopia may signify just a physiological variation in the length of the eyeball or it may be associated with precocious neurological growth during childhood. other causes are : Curvatural type Role of diet Role of genetics Theory of excessive near work Reference : A K KHURANA OPHTALMOLOGY,Edition 4, Page-33
Optics and refraction