[jackson1442]

I've found that face/retina scans are usually bad UX, especially if you need to use a viewfinder or a statically positioned device. Apple's Face ID works well because it's on a mobile device and you don't have to align your face in a box.

I don't see how this is any more convenient than using a mobile wallet. In fact, it looks less convenient than using the actual card - even if you forget the card you can usually just key in the number at the terminal.

[MBCook]

It will be just like all those little paper signs they stuck on EMV terminals. “Insert chip here”, “No chip”, “Tap card on screen”.

So how do you make people use a retinal camera? You cut a hole in a picture of a monkey or the store mascot’s head and put up a big sign that says “look at Mr. Groceries to pay your bill with MasterCard EyeScan” or whatever it is called.

Because explaining how to use it to every single person in line is definitely going to make it fast.