From the reddit comments:

Safety warning: Putting high powered IR LED near your eyes is extremely dangerous to your eyesight. The human eye does not react to IR light (or any non-visible light as I understand it). The pupillary constriction response is what protects your eyes from bright light, it doesn't work with IR, so you are in real danger of damaging your eyes if the IR is shining in your eyes with a stupid device like this. The problem is, you can't see it, or feel it, so you can't really tell it's happening. It won't cause you to blink, or squint your eyes, and the pupil won't close. Normal levels of IR are safe, but something like this could cause serious damage.