According to the article: Robin Ali at Moorfields Eye Hospital in London and colleagues are treating adults and children with Leber's congenital amaurosis (LCA), caused by an abnormality in the RPE65 gene. This gene is important in recycling retinol, a molecule that helps the retina detect light. People with LCA usually lose vision from infancy. Ali's team are inserting healthy copies of RPE65 into cells in the retina, using a viral vector. Previously, dogs with LCA have had their vision restored in this way, allowing them to walk through a maze for the first time without difficulty.