Biosensor, communicator, and/or controller apparatus, systems, and methods are provided for monitoring movement of a person's eye. The apparatus includes a device configured to be worn on a user's head, a light source for directing light towards one or both eyes of the user, one or more image guides on the device for viewing one or both eyes of the user, and one or more cameras carried on the device and coupled to the image guides for acquiring images of the eyes and/or the user's surroundings. The apparatus may include a cable and/or a transmitter for transmitting image data from the camera to a remote location, e.g., to processor and/or display for analyzing and/or displaying the image data. A system including the apparatus may be used to monitor one or more oculometric parameters, e.g., pupillary response, and/or to control a computer using the user's eyes instead of a mouse.