Sky, do you know about sigma in statistics? Our dial tone in the USA is 6 Sigma, far right, in the bell curve. That means out of every 1,000,000 opportunities for failure there is only 1 fail. Now, dial tone and death match are two different things are they not? But, here we consider the dial tone, life or death, unlike most places in this world.
So, have you ever had a fingerprint scanner on a laptop? It is not 6 Sigma. It fails. Our badge swipes at the work door, are not 6 Sigma. Hardly.
Your MacRumor is just No Sigma vapor ware. And it is not proposed for weapons. And you still have not said how you could manage a eye scan device on a weapon or what kind of Sigma we could expect.
So, no eye scan is instant. It takes software. But 2 of 3 of my Colt Commander safes are instant. The gun cannot be fired, even with the hammer back (#1 safe, is hammer down) That's 1/10 sec to cock it.
It still needs 2) hand grip instant safe in the grip, and 3) thumb switch, instant safe that goes hot, when my trigger finger goes on the trigger. It is part of the same movement.