Objective: The aim of this study is to investigate and review the previous researches about objective measuring
fatigue caused by visual stimuli. Also, we analyze possibility of new visual fatigue measurement methods using facial
expression recognition and gesture recognition. Background: In most previous researches, visual fatigue is commonly
measured by survey or interview based subjective method. However, the subjective evaluation methods can be
affected by individual feeling’s variation or other kinds of stimuli. To solve these problems, signal and image
processing based visual fatigue measurement methods have been widely researched. Method: To analyze the signal
and image processing based methods, we categorized previous works into three groups such as bio-signal based
method, brainwave based method, and eye image based method. Also, the possibility of adopting facial expression or
gesture recognition to measure visual fatigue is analyzed. Results: Bio-signal and brainwave based methods have
problems because they can be degraded by not only visual stimuli but also the other kinds of external stimuli caused
by other sense organs. In eye image based methods, using only single feature such as blink frequency or pupil size
also has problem because the single feature can be easily degraded by other kinds of emotions. Conclusion: Multi-
modal measurement method is required by fusing several features which are extracted from the bio-signal and image.
Also, some progressive method including facial expression or gesture recognition can be considered. Application:
The objective visual fatigue measurement method can be applied into the fields of quantitative and comparative
measurement of visual fatigue of next generation display devices in terms of human factor.