Effects of font size, stroke, and background on the legibility of Chinese characters in virtual reality for the elderly

To investigate the legibility of Chinese characters' font size, text background opacity, and font stroke for the elderly in virtual reality, we recruited old and young participants to conduct experiments with VR and used eye-tracking technology to record the data of task completion time and error rate. After analysis, we concluded that the minimum recognition font size for the elderly is 30 dmm, and the best font size is 60 dmm, which is 20 and 40 dmm for young people. The font style has a significant effect on old people (p = 0.000*). Besides, for font sizes smaller than 20 dmm and bigger than 50 dmm, text with strokes and over 50% semi-transparent backgrounds can improve legibility for the elderly. With a suitable font size, the influence of font style on the elderly is not significant. These conclusions can provide a reference for the elderly-oriented Chinese font design in VR.