Dr. Mark Lindsay was 5 years old when he first learned that tree trunks were brown. "Up until that point, I believed leaves and trunks were all green. Just lighter and darker shades," Mark said. Mark ...

We may earn commission from links on this page, but we only recommend products we love. Promise. Sometimes, you’re born with it; other times, it’s hair dye. But regardless of how you achieve your ...

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 ...