A Comparison of Visual Fatigue between Interlace and Non-Interlace Scan Television Screens

It is known that the flicker of characters and images displayed on the home use television screen is often perceived. This study investigated whether such a traditional television screen with flicker effects and a flickerless television screen(non-interlace scan) are different in causing visual fatigue. Each of 16 subjects had five sessions of 20 min each a screen monitoring task followed by a rest period of 20 min. A questionnaire to evaluate visual fatigue was given and dark-focus accommodation, near point accommodation and grating acuity were measured at the beginning of experiment, after each session and after the rest period. The results of the nearpoint accommodation and grating acuity indicated no significant differences between the two screens. However, the symptoms of “dryness of the eyes” was more intensive in the increased subjective rating of visual fatigue in the course of the screen monitoring task sessions in the case of a interlace scan screen than in the case of a flickerless screen. Further, the change in dark-focus accommodation during the task did not recover after the rest period of 20 min when the interlaces can screen was used. These results suggest that a flickerless television screen has the possibility of causing less visual fatigue in comparison with a traditional screen with flicker effects