SensoMotoric Instruments recently released its latest mobile eye tracking technology, called the SMI Eye Tracking Glasses 2 Wireless. It comes with wireless control and a lightweight Android smart recorder. You can record more than 4 hours of data. You can control it via WiFi from a Windows device or tablet. You can also add live annotations wirelessly while recording.
Such a solution can be used for virtual reality, shopper insight, and neuromarketing studies. The platform comes with an SDK which supports real-time data streaming. Not cheap but can be quite useful for research.