For the first time ever, scientists have managed to 3D-print human corneas, which - once perfected - could restore vision to millions of people.
Stem cells from a healthy donor cornea were mixed together with alginate and collagen to create a solution that could be printed using a simple low-cost 3D bio-printer. The bio-ink was successfully projected to make a human cornea, and it took less than 10 minutes to print.