Abstract
Purpose:
To investigate whether the black text on white background setting for textual displays produces the best reading experience, speed, and accuracy in the visually impaired vs. healthy eyed.
Methods:
This is a prospective study in which ophthalmology patient volunteers participated in an iPad reading game, in which patients were asked to select “yes” or “no” for whether or not characters matched displayed instructions. Variations of the same game are administered under 4 different settings in a random order: 1) black text on white background (BOW), 2) white on black, 3) choice color text on complementary background self-selected from 6 options (cyan on red, orange on blue, yellow on purple, and their respective reverse combinations), and 4) reverse choice combination. Objective endpoints include accuracy and speed. Subjective endpoints are survey results of reading experience, ease of reading, and accuracy of performance.
Results:
110 subjects completed the study. 13 were healthy eyed and all others had cataracts, hypertensive retinopathy, PVD, CME, NPDR, wet AMD, glaucoma, or a combination of the above. Independent T-tests between disease subgroups vs. healthy controls showed that healthy controls performed faster (p<0.05) in both BOW and color choice settings, the latter having a greater effect size. However, difference in accuracy was not observed in any subgroup comparison to healthy patients. Within-group paired T-tests revealed significantly higher speed and accuracy on BOW compared to non-BOW setting of choice in cataract and NPDR subgroups. Healthy controls and the other disease subgroups did not reveal statistical significant difference in objective parameters under choice vs. BOW settings.
Conclusions:
The visually impaired read slower but not less accurately than their healthy counterparts. In healthy eyed and patients with HR, PVD, CME, AMD and glaucoma, speed and accuracy are not affected by color when compared against the conventional BOW setting with maximum contrast. However, those with cataract and NPDR do perform slower and less accurately in non-BOW settings. These results suggest that while BOW maximizes speed and accuracy of reading in certain subgroups of eye disorders, it may not create advantages for the majority of people including those with healthy vision. There is room for reading optimization tools that take into account subjective and objective parameters in producing the best individual reading experience.
Keywords: 672 reading •
471 color vision •
412 age-related macular degeneration