Mobile computing devices facilitate our daily lives, however, overuse of such may cause visual discomfort or even injure our eyes. Thus, personal visual health management is very important. Current eye fatigue examination methods include the critical flicker fusion test and Heuer's 10-point scale questionnaire. However, the flicker fusion system is too heavy and too expensive for general use by average consumers, and the 10-point questionnaire appears to be subjective and is thus unsuitable for personal visual health management. We herein propose a spatial frequency-based testing method. In the proposed testing method, the user is asked to identify a specific square grid from among several objects of the same size. By increasing the spatial frequency of the grids, we can determine the highest critical frequency the user can observe. By comparing the test results to those of Heuer's questionnaire, we can determine the relationship between eye fatigue and critical spatial frequency. Thus, the proposed method is promising for eye fatigue detection and can be used for personal visual health management.