Systems and techniques are described for extended reality (XR) operations. An XR system displays virtual content using a display according to display settings. The display settings can identify, for instance, a position, orientation, and/or size of the virtual content as displayed. The environment can be viewable using the display as the virtual content is displayed by the display, for example using a see-through display or a pass-through display. The imaging system can determine, based on one or more attributes of one or both eyes of the user of the imaging system, an extent of perception of the virtual content that is displayed using the display by the user. The attributes can identify, for instance, eye position, eye movement, pupil dilation, saccades, fixations, blinking, and/or squinting. The XR system can determine, based on the extent of perception of the virtual content by the user, a modification to the display settings.