DailyTech reports scientists at the SUNY Upstate Medical University, in Syracuse, NY, have grown new frog eyes from stem cells and successfully implanted the new eye to restore a frog's sight:
In order to get the cells to become eyes, the team genetically modified them, inserting transcription factors (proteins that trigger expression of other genes) which are known to regulate eye growth and development.
The scientists then implanted the cells into tadpoles missing an eye. The cells properly developed and differentiated into all seven types of retinal cells and appeared to have the proper structure. Additionally the new eye attached properly to the brain. In swimming tests the eye was shown to be working as implanted tadpoles only swam to the white side of the tank (normal behavior), while blind ones would also swam to the black side of the tank.
The discovery could one day restore sight in humans, but the researchers note regrowing tissue in mammals is much more complex. However, even if a full eye could not be grown, the discovery could still be of help to people with retinal disorders.