A number of groups are working on stem cell based regenerative therapies for eyes. As noted by the BBC, human adult retinal stem cells have been shown to form the right tissue when implanted into mice: "When their eyes fully developed, the human cells survived, migrated into the sensory part of the eye and formed the correct cells. ... This will help them find out whether retinal stem cells can be used to treat degenerative diseases of the retina such as retinitis pigmentosa and macular degeneration, which are among the most common forms of blindness in developed countries." This is early stage work, but successful strategies for managing stem cells in one project help to advance many others.