Abstract
Abstract: :
Purpose: The objective of this study was to measure the effects of font smoothing font type, and stroke width upon legibility. Methods:Thirty subjects (age 18 to 35 years), with best–corrected acuity of 20/20 or better participated in the study. Capital letter, lower case letter and lower case word legibility were measured with 6 fonts (Georgia, Times New Roman, Plantin, Verdana, Arial, and Franklin), 3 font smoothing modes (none, gray scale and ClearType), and 4 stroke widths of Franklin Gothic font. Visual acuity was measured on each subject for the various parameter combinations, using stepped viewing distances to create acuity line steps. The mean visual acuity of the subject group for each condition represents the relative legibility for the condition. All testing was performed using a 12–pt font (block size) on an LCD screen. Main effects and interaction effects were tested for statistical significance with repeated measures ANOVA. Results: Upper case letters were more legible than lower case letters (p<0.0001) and lower case words were 10% less legible than their component individual letters. Font smoothing affected legibility (p<0.0001), ClearType was more legible than gray scale. Font type had a significant effect on legibility (p<0.0001). Legibility was significantly better with Verdana and Arial fonts than with TNR and Franklin, sans serif fonts were generally more legibility than serif fonts. Thin stroke letters were less legible than the thicker strokes. Significant interaction was measured between font smoothing and font type, the combination of ClearType and Verdana offered greatest legibility. Conclusions:Sans serif fonts had better legibility than serif fonts. Heavier stroke widths were more legible than thin stroke widths. Words were less legible than their component letters.
Keywords: visual acuity • reading