Are you color blind? Maybe you are, maybe you aren't—but have you ever put that question to an actual test? You can, and it's very simple.
Tests your color vision. If you're color blind, it will tell you how color blind you are, and what kind of deficiency you have.
There is a Counting Crows joke in here somewhere, but all kidding aside, color blindness is really, really common. If you've never checked, you probably would like to know definitively whether or not your among the millions of people who have defective cone cells in the eyeball region. And if you have to subject yourself to a vision test, you might as well do it in a beautifully designed app like this one.S