How can i make my eye whites whiter?

Depends : Red eyes can be from inflammation from chronic allergies, dry eye syndrome, blepharitis (minor infection of the eyelid margin), meibomianitis (blocked ducts on eyelid margin, and from benign vascular growths on the conjunctiva called pinguecula (can grow into the cornea then called a pterygium). You need the right diagnosis to get the treatment to get rid of red eyes. You need an eye exam.

Lubricate!: You can try lubricating the eyes with artificial tears one drop 3-4 times a day and taking oral omega 3's like evoa dry eye supplements to stimulate more and better tear production. This will work if they are red due to dryness. Some people just do not have as white as eyes as others. There is nothing you can do to change this that I am aware of. Could be more serious, if this does not help.