EnChroma covered in SF Chronicle
At the back of the eye, there are three types of color-sensing cells, called cones, that respond to different parts of the spectrum of light: blue, green and red. The three overlap somewhat, but in the case of a red-green deficiency, the cones’ responses to green and red overlap too much. That causes the red and green cones to send the same, or almost the same, information to the brain, which then has difficulty discriminating between the colors. This confusion also leads the brain to mix up blended, muted colors that contain red or green, such as purple.
The proprietary lens contains a filter that blocks a portion of the spectrum where the overlap between the two cones occurs and restores the separation between them. “It’s essentially taking out that stuff that’s confusing the signal,” said Andy Schmeder, vice president of technology.
–Stephanie M. Lee
Read more at SFGate.com in her article: Glasses help color-blind see trees of green, red roses, too. Published in print Jan 1 2015.