Many studies use eye-tracker to analyse the socio-technical system, also in medical research. Only a few articles describe the use of eye-tracker to examine human-computer interaction in a critical care environment, especially in the field of anaesthesia or surgery. Therefore, we have tested in a feasibility study head-mounted eye-tracker of three different manufactures in a simulated anesthesia surrounding with mankind patient simulators. The research question was to analyse whether the field scene camera of the eye-tracker can be used in the light conditions and changes in brightness of the operating room. In addition, it was tested whether the eye-tracker was still calibrated and held on the subject’s head during the resuscitation movement. All eye-trackers tested had a good adaptation on changing light or changing distances.