3 ms·

Some people don't have eyes.

• inglor_cz 6y ago
  True, but that might not be a limitation for some implementations, such as authenticating employees coming to specific jobs. Blind pilots or surgeons aren't a thing.
  • ravi-delia 6y ago
    In the future they may be, which brings up another issue: what about people who lop out their eyes for a better replacement?
    • m463 6y ago
      Are you talking about Tom Cruise? :)