The question is quite vague because we usually take medicine for certain disease. If you don't have any eye problem. you don't need to take medicine because every medicine can have side effect on your body. To maintain good eye health, a nutritious diet, not smoking, enough rest, low stress and lutein capsules will decrease your risk of developing serious eye diseases in the future.
I don't know which kind of medicine is best for eye health. You can have a look at any drug stores. There are many kinds of health care products. Maybe you can find what you want quickly. I don't take medicines to improve my eye health. I just keep a healthy diet and take care of my eyes now I have perfect vision.
I won't suggest you to take medicines to improve your eye health. Our eyes are very flexible. If you protect them in everyday life, they can function well. Some people believe that there are many medicines that can cure all the disease or prevent the disease from happening so they don't need to take care of their health. But I think the most important way to maintain a healthy body or healthy eyes is to take care of them in every day lives. First, nutrients and vitamins are very important for our eyes. Second, relax your eyes if you feel tired. Third, pay attention to eye hygiene. Fourth, avoid possible damages to your eyes. Maybe there are some things that I haven't mentioned at this time, but if you think they are good for your eyes, you can do them.