Those with color blindness see only about 10,000 to 100,000 different hues. A vastly diminished color spectrum. Here's how the glasses can help. Most people have three color cones in their eyes.
"Up until that point, I believed leaves and trunks were all green. Just lighter and darker shades," Mark said. Mark had discovered he was color blind. Color blindness, or color vision deficiency (CVD) ...
A Virginia state park has new technology in special viewfinders that allow people who are color blind to see the full color spectrum of the fall foliage. NBC News' Valerie Castro visits the park ...