Pilestone TP-023 Yellow Lens Color Blind Glasses Clip-on for Yellow Blindness Indoor/Ourdoor Use

It could be that my son is an anomaly, but he was able to see MOST colors...With the glasses on, purple looked red. With them off, it was blue. However, he could finally distinguish white from yellow, and orange from red! Such a difference for a teen with aspirations for digital design!