In my opinion,there are many ways for you to choose to make your eyes completely white.I hope they can take effect.Firstly,a very effective way to achieve completely white eyes is to use drops containing a vascular constrictor,because it constricts all of the blood vessels in your eyes making them instantly sparkling white.This way is really fit for cosplay. Secondly,making up is another way to help you to realize your purpose. Namely, using white eyeliner,it will make the eye much whiter.Thirdly,it can reach your purpose without anything.As known to us,our eyes are made up black eyeball and some white crystals.So you just turn your white crystals up.Then your eyes are completely white.I am fond of this way as it needs nothing .Of course,there will be other ways to make eyes white.I hope what i have said can help you a lot.Thank you!