how to improve my Eye sight?

actually i am not wearing any glasses or contact lenses,i have problem when i am in 6th class now i completed my engneering, when i am in 6th class i have -0.75 eye sight and at 10th class i am having -1.5 Eyesight,upto 10th class i used to wear the glasses,from inter i am not wearing it,now i am having -3.25 eye sight,i dont want to wear glasses please suggest me any exercises and diet to improve my Eye Vision,ya one way is there i know that laser operation but it costs a lot,i cant able to bear huge amount i belonged to middle class society.

Good vision is a vital part of feeling your best. We rely on sight more than any other sense to enjoy life to the fullest. Your vision changes naturally throughout your life. There are also three steps you can take to help take care of your sight:

Visit an eye doctor regularly.
Make changes to help yourself see better.
Take care of yourself.

Exercises to Improve Eyesight – Better Vision For and From Better Memory