Assessment of the function of the visual system in the acute phase after head injury is often difficult, since consciousness may be affected. In this report, we wish to stress that combined electroretinography and the averaged visual evoked potential should be the examinations of choice because they do not depend on the patient’s cooperation or state of consciousness. The case histories of five patients are reported. Only by means of the electrophysiological methods was a diagnosis made possible, since clinical examinations failed to clarify the state of their visual system