ViewPointer: lightweight calibration-free eye tracking for ubiquitous handsfree deixis

We introduce ViewPointer, a wearable eye contact sensor that detects deixis towards ubiquitous computers embedded in real world objects. ViewPointer consists of a small wearable camera no more obtrusive than a common Bluetooth headset. ViewPointer allows any real-world object to be augmented with eye contact sensing capabilities, simply by embedding a small infrared (IR) tag. The headset camera detects when a user is looking at an infrared tag by determining whether the reflection of the tag on the cornea of the user's eye appears sufficiently central to the pupil. ViewPointer not only allows any object to become an eye contact sensing appliance, it also allows identification of users and transmission of data to the user through the object. We present a novel encoding scheme used to uniquely identify ViewPointer tags, as well as a method for transmitting URLs over tags. We present a number of scenarios of application as well as an analysis of design principles. We conclude eye contact sensing input is best utilized to provide context to action.