Are there any ways to improve eyesight?

Yes: Glasses contact lens or lasik can improve your eyesight by enhancing the optics. However without help improved vision will not occurr on its own.

Depends on cause: Eyesight can diminish in many ways. The most common is a need for eyeglasses but there are a number of disease such as glaucoma, diabetes, keratoconus and others which can affect eyesight. Best to get a good evaluation with an ophthalmologist to be sure which category you fall in so that the best treatment can be given.