That said, the results do come with caveats: long-term success rates and risks have yet to be determined. And whether or not the donor stem cells will persist, for example, is unknown. Still, the development offers great promise for treating corneal damage and, more broadly, damage to other epithelial tissues, such as the the lung and the gastrointestinal tract. "The really exciting thing is where this can take us," Schwab enthuses. "Replacing diseased tissues and organs with bioengineered tissue is rapidly moving from the realm of science fiction to reality."