My experience with evaluating consumer medical devices ("lifestyle" and "fitness") is that what is on the box is often not what the device actually does. Besides wavelength and wattage, you would probably need to check for consistency, whether there aren't any spikes, etc. I don't know how much IR light is dangerous for the brain / what tolerances are acceptable.

I would not use it without proper eye protection for that particular wavelength. Staring into an infrared light will probably negatively affect your eyesight. As the eyes cannot see it, your pupil will not react and you also can't judge how bright it is.

More is not better. Research suggests optimal mJ/c^2/s dosages for each wavelength. Stuff on amazon is not going to be calibrated at all to dosage or even wavelength. Aside from being ineffective, there aren't dangerous side effects except prolonged exposure if staring into high intensity NIR.