How to increase eyes power to remove spex completly and naturaly?

Unfortunately none. The need for prescription eyeglasses is not a disease state, but is actually determined by the shape of the eye. For example, nearsighted individuals tend to have longer eyes, farsighted people have shorter eyes and those with astigmatism have corneas that are slightly oblong rather than round. No exercises or medicines can change the eye's shape - only corrective lenses and surgery can do this.
Depends. Depends on the health of your eyes and general health. Advise you get a check up with a ophthamologist (eye doctor) to check on the health of your eyes to determine why you need glasses and ask if there is therapy for any conditions you have.