Is this common? Airport scanners are usually face scanners. Iris scanners are almost always for employees with access to critical areas, not for travelers. I know Doha and Singapore airports use iris scanners at the security check. It's probably a growing trend, haven't seen any in the EU, is it already common in the US?

The normal TSA pre-check lines make you scan your face too. They used to read "images are deleted after use" but I didn't notice that message last time I went through security. So likely it's being used by ICE now.

The customs line have been doing much more rigorous face scanning for a while now.