Clear is now a TSA “vendor” for the precheck process. The machines they use for the sign up process - at least the airport I was at - don’t have the eye scanning camera in the kiosk.
The Clear representative I was asking questions of had said they don’t require eye scans for Clear, though that is the default. People can ask to use just fingerprints, which he said does disrupt the terminal process as the agents don’t think to ask if fingerprints were what was registered when the eye scans fail.
I am not advocating for Clear. I refuse to use them. I simply do want to call out that they are one of 3 who handle the process for the TSA now. People do have a choice of which of the three to use.