A system for determining the gaze direction of a subject includes a camera, a computing device and a machine-readable instruction set. The camera is positioned in an environment to capture image data of head of a subject. The computing device is communicatively coupled to the camera and the computing device includes a processor and a non-transitory computer-readable memory. The machine-readable instruction set is stored in the non-transitory computer-readable memory and causes the computing device to: receive image data from the camera, analyze the image data using a convolutional neural network trained on an image dataset comprising images of a head of a subject captured from viewpoints distributed around up to 360-degrees of head yaw, and predict a gaze direction vector of the subject based upon a combination of head appearance and eye appearance image data from the image dataset.