kengr

Scleral lenses, with vantablack embedded in the material so it doesn't actually come in contact with the eyes.

Problem is, vantablack is a surface effect, it's basically just carbon, graphite specifically, but the light is absorbed by it because of the way nano scale plates are stacked into pillars of alternating big and little plates to produce a light trapping surface. Embedding it into a clear material might change it's optical properties.

However, MIT have come up with something even blacker than vantablack, and more robust. Link here

That shows more promise for the uses you suggested. Plus, it's still carbon so biological safe.