Retinal cells made from human embryonic stem cells could one day be used to help restore sight in people with certain forms of blindness.

Yoshiki Sasai at the RIKEN Center for Developmental Biology in Kobe, Japan, and his colleagues used the stem cells to generate retinal epithelial cells, which are precursors for the retina. After a few weeks, a single layer of these cells spontaneously formed a curved structure called an optic cup. After several more weeks, the cup developed into a multilayered structure with multiple retinal cell types, including light-sensitive photoreceptors.

The researchers also devised a method for cryopreserving the retinal tissue. They foresee that stored material could ultimately be triggered to develop into specific cell types that can be grafted onto a patient's retina.

Cell Stem Cell 10, 771–785 (2012)