Eye Grown Out of Stem Cells
According to this article in the The Guardian, scientists were able to use embryonic stem cells to build a simple but functioning eye.

Scientists have used stem cells to grow a rudimentary eye in the laboratory in a landmark study that raises the prospect of creating tissues to treat blindness and tease apart how diseases can destroy eyesight.

The Japanese team is the first to make significant progress in turning embryonic stem cells into an organ as complex as the eye.