<Snipped quote by Nimda>
Whenever you're ready. We can either get you brand new eyes or upgrade your natural ones. And they'll look like this. *My eyes change several times to show four different things as I list them* There's Sharingan, Byakugan, Tenseigan, and the Rinnegan. You could even get one in each eye to have two, but having multiple like me would be too much of a strain on you. The Sharingan also only shows up visibly when active, but the other three are always active and visible.
What are the differences and advantages of new eyes vs. altering my own? And would I ever be able to train myself up to have multiple?