<prompt> Shoening of 2 mm of axial lengsth of eye ball causes -3D myopia6D myopia3D hypermetropia6D hypermetropia  <response>: 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 