US Patent 11687636 Pupil dilation response for authentication

A user's emotion can be determined based on pupil dilation response to a challenge prompt. In response to an authentication request, a registered challenge prompt and an expected pupil dilation response can be retrieved. The challenge prompt can include one or more images or a video designed to cause a pupil dilation response in a user. The challenge prompt is displayed to the user and the user's pupil dilation response is captured. At least one user action of the user is monitored and an emotion is determined based on the at least one user action. The emotion is associated with the pupil dilation response.