In order to let your whites of the eyes become whiter, you could eat the wild chrysanthemum, wolfberry and longan. This is the best way for you to eat. Your eyes will become so bright, making the white parts of the eyes become whiter. You could just have a try.
Well, it seems that your eyes are not in good conditions and you want to improve your eye health. So, as far as I know, if there is something wrong with the whites of the eyeball, such as other kinds of colors, there are perhaps some diseases. So, if you want the whites of your eyes stay normal and improve, you should identify some possible causes for abnormal signs on the whites and eat something healthy like vitamin-B-rich vegetables.
In general, if your eyes whiter is not so white, you may lack of water and your body is relatively wet. You can drink more water, eat more foods improving eyesight things and vitamins, such as some green vegetables and fruits. In addition to the food therapy, you should do some exercise everyday, because a health person must be in fine fettle.