Human eyes have the potential to regenerate their own lenses after surgery—as long as surgeons leave the right kind of cells in, STAT reports. When operating on cataracts, surgeons simply replace the cloudy lens with an artificial one. But this can cause all kinds of complications, often requiring more surgery down the line. Now, a new study shows that if lens epithelial stem cells are left behind after surgery, the lenses of infants can recover by themselves in 3 months. Not only did these infants experience fewer complications than those receiving traditional surgery, but their lenses were also 20 times clearer than the artificial lenses, the researchers report today in Nature. Next, the researchers plan to test this technique on the elderly, a group with much higher rates of cataracts than infants.