Hello, I have been using contact lens since 2 years and I have a power of -8, coming to problem. There is a change in position of my eyeball in my right eye and it looks like squint, the wrong thing I have done is I have used an expired lens for few days can any one please tell me the reason for it and also the treatment And I usually ride bike for long times this causes burning in my eyes please suggest me some good eye drops.