Does rubbing the eyes frequently or vigorously really changes the shape/curvature of the cornea to induce - 0.25 or -0.50 change of power? My local opthalmologist was telling it can happen but many doctors on internet write that rubbing does not change the shape of a normal eye . Or it is rather the another way around that genetics of minor power changes are already there but rubbing induces or accelerates this genetic predisposition. I request you to clarify my doubts here as we are dealing with a normal eye here and not the one with kerataconus . How does rubbing really affect it then or what are the other factors that affect the shape of cornea becoming oval  and that too at the age of 25. Vision was normal till age 19 then diagnosed with refractive errors of -0.25 cylinder at age of 21 and -0.50 cylinder at age of 25 respectively