Reading performance in middle-aged adults with declines in accommodation.
The present study investigated the effects of presbyopia on the reading ability of middle-aged adults in a Japanese reading context, using the rapid serial visual presentation paradigm. Japanese words, each consisting of three characters, were sequentially presented at the same location on a display screen. Participants were instructed to read the words aloud as accurately as possible, irrespective of their order within the sequence. Experiment 1 showed that the reading performance for the presbyopes was far worse for the near-viewing (35 cm) than for the far-viewing (70 cm) conditions when the words were presented at 0.4° in character size. Experiment 2 investigated in detail the effect of luminance contrast on reading at a viewing distance of 35 cm. The minimums of the exposure durations within which the participants could read the words above 89.9 % correct (minimum exposure duration) were 498 ms/word for the presbyopes and 134 ms/word for the nonpresbyopes, both of which values were obtained at 100 % contrast. The critical contrast-that is, the contrast that doubled the minimum exposure duration that had been obtained at 100 % contrast-was considerably higher for the presbyopes (39.2 %) than for the nonpresbyopes (16.4 %). However, the reading performance for the presbyopes was improved more than threefold when the contrast was increased to 100 % in both experiments. Thus, our results provide psychophysical evidence for the dependency of presbyopes' reading on viewing distance and luminance contrast.
Cognition and Action Lab, Department of Computer Science and Systems Engineering, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran, Hokkaido, Japan. wataru.teramoto@gmail.com
Wataru
W
Teramoto
Kosuke
K
Tao
Kaoru
K
Sekiyama
Shuji
S
Mori
D000065:Accommodation, Ocular; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000503:physiopathology; D011932:Reading; D014785:Vision, Ocular; D055815:Young Adult