Eye Glint as a Novel Perceptual Cue in Human Vision.

A subtle yet ubiquitous feature of the human face is eye glint-specular reflections from the surface of the eye that vary with the position of light sources in the environment. This study tested whether eye glint influences face perception, particularly in how observers perceive the gaze direction of a person they are viewing. Adult participants viewed computer-rendered face images that varied in eye direction, head rotation, and illumination. The presence of eye glint had little influence on the accuracy or precision of perceived gaze direction when faces were viewed under simplified conditions. However, biases in perceived gaze direction caused by changes in head orientation or illumination direction were reduced when eye glint was present relative to when it was absent. This suggests that eye glint can help an observer to maintain constancy in gaze perception despite variability in the appearance of the eye region that occurs across viewing conditions.