What can i use (safely) to get the whitest eyes possible?

Preventive is best: There really isn't anything that's safe. Visine can temporarily whiten your eyes, but prolonged use can make it worse. Best thing to do, is always get plenty of rest, adequate sleep at night, try not of over abuse your eyes (being on the computer 8 straight hours a day) wear sunglasses, and use artificial tears without preservatives. They do have surgery to whiten your eyes, but not safe.