I ran across this webpage that’s part of the PSP genetic and environmental risk factors study:
The first set of pictures is about voluntary vs. involuntary eye movement:
“The upper left hand picture shows this PSP patient’s difficulty in voluntarily looking upwards; however, as can be observed in the lower picture, with moving the head downwards (doll’s head maneuver), his eyes go upward, showing that he does not have an involvement of the oculomotor nuclei in the brainstem. The lesion, rather, is above these nuclei, showing the patient’s vertical supranuclear gaze palsy.”
Note that “supranuclear” refers to the pathology being above the oculomotor nuclei. “Palsy” refers to the eyes.
The lower picture shows someone with a “classic” PSP stare:
“The picture to the left shows a patient exhibiting what is called a ‘staring face,’ due to her difficulties in moving her eyes, decreased blinking and some facial ‘dystonia’.”