Here's some seemingly obvious advice: don't get your eye ball tattooed! Catt Gallinger, a 24-year-old model from Canada, didn't think her decision through when she decided to get her sclera, which is the white part of your eyeball, tinted purple. Instead of stupid looking eyes, Catt's eye ended up swollen and oozing purple liquid. Medical professionals think the equipment used on Catt's tattoo may not have been sterile, and have told her she'll never fully recover and her eyesight will remain compromised or potentially worsen. So sterile needles or not, it's probably best to avoid the sclera tattoo all together.
Personally...you couldn't PAY me enough to have tattoo needles jabbed in my eyes!