1. An image system comprising: an image sensor having a predetermined field of view and configured to capture an image; a display screen; a face detection engine electrically coupled to the image sensor and configured to recognize a face in the image; an eye detection engine electrically coupled to the image sensor and configured to recognize eyes in the image; and an eye protection engine electrically coupled to the display screen, the face detection engine and the eye detection engine, and configured to switch off the display screen when the eyes are recognized by the eye detection engine but the face is not recognized by the face detection engine.