Don McPherson, a San Francisco-based researcher, designed protective glasses for surgeons to wear during laser surgery. But when it turned out the glasses had a surprising second utility—they helped correct color vision deficiencies and color blindness—a YouTube subgenre was born. The clips, with emotional, ebullient reactions to the glasses from people who saw corrected color for the first time, were overnight hits.
Among the videos’ charms are the stories they've produced online, among them many people who said they were in their 20s before the realized peanut butter was brown, not green, as they had always believed. The video above briefly explains the glasses, how different color deficiencies work, and what exactly colorblind people see when they look at grocery-store produce and other colorful displays.