Astigmatism in right eye. Could this ever somehow improve on its own (even slightly), and if not, why?

Changes. Astigmatism comes from changes in corneal curvature over time and can vary (worsening, stable, or improving). Furthermore, astigmatism can also be from the lens or retina too. The former, as a result of aging, can be removed during cataract surgery. Retinal astigmatism, usually the result of retinal surface membranes, may be surgically treated. Mostly though, corneal astigmatism is treated by Rx. .