Instead of replacing one damaged cornea with one healthy one, you could grow enough cells from one donated cornea to print 50 artificial ones

From Scientists have 3D printed the most advanced artificial cornea ever using human cells – The Verge

It was tricky to find the right recipe for an ink that’s thin enough to squirt through a 3D printer’s nozzle, says Che Connon, a tissue engineer at Newcastle University who was one of the creators of the artificial cornea. This bio-ink didn’t just have to be thin — it also had to be stiff enough that it could hold its shape as a 3D structure. To get the right consistency, the researchers added a jelly-like goo called alginate and stem cells extracted from donor corneas, along with some ropy proteins called collagen.

But there’s still a long way to go before these artificial corneas will even get close to a human eyeball: Connon wants to fine tune the printing process first, he says, and the artificial cornea will also need to go through safety studies in animals. But this study is proof that you can 3D print something that looks like a cornea, and contains mostly the same ingredients. It’s also the first time researchers have recreated the cornea’s distinctive, curved shape.

If and when this technique is perfected, tech-augmented corneas in place of smart contact lenses is not an unthinkable scenario.