According to The New York Times, a new development in stem cell research emerged after an extensive trial on patients with eye diseases. A study published in The Lancet looked at 18 patients with eye diseases, following their progress for a median of 22 months. Researchers transformed stem cells cells into retinal pigment epithelium cells, implanting them into one eye on each of the patients. In 8 of the 18 participants, vision improved significantly in the treated eye. An additional five participants showed increased pigment levels, marking the newfound presence of the injected cells, though higher pigment levels did not necessarily correlate with improved vision.