It even looks like there’s software thay lets it run on Linux. Was it accurate enough for, like, desktop use? Did he have to hold his head still?
It wouldn’t take much to make it impractical: being fussy enough that you have to think about using it while you are would defeat the purpose. Any inaccuracy, or not being granular enough, or requiring you to hold your head still, not working with glasses, or lag… those would all kill it.