One day during an ultimate Frisbee game, a friend put on glasses McPherson was using to protect his eyes when performing laser eye surgery on patients, and realized he could see the orange cones for the very first time.
Seven years later, the idea became EnChroma, a company that helps people who are colorblind see color.
Barbara Lann cried the first time she put on her EnChroma glasses.
"It was amazing from the minute I put them on," Lann said. "I didn't realize that it wasn't just greens that I was not seeing, it was also blues, browns, reds."
McPherson spent thirteen years studying color vision. Designing a lens that improved color discrimination for the color blind was the first step, but understanding how the glasses helped peoples' color vision took a lot longer. In normal color vision, blue, red, and green photo pigments are separate. With colorblindness, red and green overlap, causing colors to become muddled.
"Our filter comes in and moves it back to normal position," McPherson said. "Now you're sending the correct information to the brain and those neuromechanisms, which have been dormant their entire life, are suddenly activated."
Using CEO Andy Schmeder's mathematical modeling expertise and three NIH SBIR grants, EnChroma was born in 2010.
"In the world, there's an estimated 200 to 300 million that have colorblindness," Schmeder said. "Right now, we've been able to help tens of thousands of those. It's such a tiny, tiny percentage."
McPherson and Schmeder hope to bring color to many more people, especially children.