Is there anything that you can to do keep your eyesight from getting worse?

My eyesight is getting a lot worse lately and I was wondering if theres anything that can be done to prevent it from getting worse? I have to spend a good amount of time on the computer because of my work, but I try to take breaks and all that to prevent eye strain. I also eat pretty healthy and take a multi vitamin. Is there anythign else I could do? Thanks!