<prompt> The most common cause of myopia is -A-P diameter is increasedThe thickness of lens is increasedThe viscosity of squous humour is increasedThe viscisity of vitous humour is increased  <response>: 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 