Is there any way to prevent eyesight from getting progressively worse?

Care. The main thing wold be to take good care of your eyes. The natural genetic progression of how your how ages and your vision changes cannot be changed unless you have some form of surgery such as lasik or cataract removal with the placement of an intraocular lens. In lieu of that, you can protect your eyes by wearing sunglasses with 100% uva & uvb blockers and sports goggles when engaged in sports.