A large U.S. health records study suggests that difficulty seeing blood in urine may put color-blind patients at higher risk.

You’ve never seen these ones before! You might have taken color blindness tests with numbers online or when getting your eyes checked at the doctor’s, but I guarantee you haven’t seen these pictures!

There are three main types of color vision deficiency: red-green, blue-yellow, and complete. Color blindness, or color vision deficiency, affects the way you perceive color and can make it hard to ...