I read up a lot on this subject on some aeromedical pages that are linked from the jet careers site. There are multivitamin supplements available at vitamin stores that contain all of the essential components for good eye health. There are a whole bunch of them, but the main ingredients. The main component in the supplement I have has Lutein, vitamin C, and E. I believe that the primary benefit of taking these supplements is to protect from long term oxidation damage and also improve night vision.