University of Alberta researchers discovered that a zebrafish's stem cells can selectively regenerate damaged photoreceptor cells.
According to lead researcher Ted Allison, geneticists have known for some time that stem cells in zebrafish - unlike those in humans - can replace damaged cells involved in many components of eyesight.
Rods and cones are the most important photoreceptors. In humans, rods provide us with night vision and cones give us a full-colour look at the world during the day.
What was not known, says Allison, was whether the zebrafish stem cells could be instructed to replace only the cones in its retina. This could have important implications for human eyesight.
"This is the first time in an animal research model that stem cells have only repaired damaged cones,