Age old question. There are many programs for sale which promise "natural" eyesight correction. They can be quite profitable for the peddlers but will not improve eyesight. There is no natural to improve the eyesight - only glasses, contacts, laser surgery are the options to correct eyesight.
Improving Eye Sight. You probably cannot improve your eyesight through natural means. Vision is a complex process and your brain needs many steps to be in sync for normal vision to occur. The number one reason patients don't have perfect vision is that they have some sort of refractive error. Either being far sighted or near sighted. These conditions are correctable with lenses or refractive surgery.