Effects of color and background luminance on minimal legible size of dynamic Chinese characters presented on a LCD monitor for low-vision and normally sighted users

• Published in: Journal of the Society for Information Display Vol. 18; no. 5; pp. 368 - 375
• Main Author: Huang, Kuo-Chen
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-05-2010
• Subjects: dynamic Chinese character; Minimal legible size; visually impaired people
• ISSN: 1071-0922; 1938-3657
• DOI: 10.1889/JSID18.5.368

— The effects of velocity (3, 5, and 7 cm/sec), stimulus color (red, green, and blue), and background luminance (20–80% white, in increments of 15%) on minimal legible size of dynamic Chinese characters, were examined. Participants were divided into low‐vision, severely myopic, and normal‐vision groups. They were asked to recognize the stimulus Chinese characters, which were presented with varying velocity on a screen. Analysis showed that the minimal legible size was significantly greater for those in the low‐vision and severely myopic groups than for those in the normal‐vision group, and the minimal legible size for the low‐vision group was greater than that for the severely myopic group. The minimal legible size was significantly greater when the stimuli were green than when they were red or blue; however, no significant difference was found between green and blue stimuli or between blue and red ones. An effect was observed for background luminance: a higher ratio of white in the gray background yielded a smaller minimal legible size than did a lower ratio of white. Additionally, velocity significantly affected the minimal legible size: a velocity of 3 cm/sec resulted in lower minimal legible size than did a velocity of 7 cm/sec. Results have implications for electronic text information design or icon design for visually impaired individuals.