Eye fatigue assessment using unobtrusive eye tracker

More than 80% sensory information our brains receive come from the eyes. Eye fatigue and associated eye diseases become increasingly severe as digital devices progress in the last decade. Visual behaviors are controlled by different parts of muscles in human vision system. One can relax and protect his eyes timely if he knows when and how fatigued his eyes are. However, people usually have no sensation when the muscles suffer from fatigue. Thus, subjective assessments of eye fatigue are inaccurate. Objective assessments are more reliable. Some of the previous objective eye fatigue assessment methods depended on complex and expensive equipment, such as EEG, which made the user feel obtrusive. Some other methods depended on eye tracker. However, they didn't provide a widely accepted definition of eye fatigue. Moreover, most of the existing methods can only tell whether the fatigue occurs but cannot provide the fatigue level. In this paper, we provide a novel definition of eye fatigue based on seven optometry metrics. An unobtrusive eye tracker is used to do the assessment. Two real-time eye fatigue assessment models are proposed based on eye movement data and eye blink data, respectively. As a result, both of our models can provide an accurate eye fatigue level to users.