Qualcomm has partnered with Tobii for mobile VR eye tracking as well as mobile AR eye tracking. In an effort to make mobile AR and VR headsets better and bring them more in line with the headsets that you can use with your PC, the two companies will work together to make eye tracking available on mobile headsets that are powered by the Snapdragon 845 chipset, which would suggest that any headsets based on this partnership that would come powered by the Qualcomm CPU are going to be self-contained.
According to the official announcement both companies will be working to deliver a reference design for the eye tracking hardware which will be based on EyeCore hardware designs and algorithms from Tobii, which will then work with HMD manufacturers for the optical hardware for the reference design headsets. A number of benefits would come to the user who is wearing a headset based on the reference designs coming out of the deal between Qualcomm and Tobii, including better hand-eye coordination. Eye tracking would allow for a better synchronicity between the eye and hand movements, which should help to improve the immersion factor and make the content that much more enjoyable.
In addition to the hand-eye coordination, bringing eye tracking technology to mobile AR and VR headsets will enable foveated rendering which is going to be a big boost to the graphical side of things. With foveated rendering the headset will be able to recognize where the wearer is looking and then divert the majority of resources and power from the CPU and GPU to that particular spot in the content to improve the graphics in real-time. It'll also help cut down on the use of battery power since the processing power from the chipset won't be scattered. Tobii views eye tracking technology as a necessary component for the next generation of headsets, so it shouldn't be a surprise that it's taking the steps to work towards that goal and bring the technology to more users.