Review Article - Journal of Clinical Ophthalmology (2021) Volume 5, Issue 1

The reciprocal relationship between letter size and luminance contrast when reading

Reading is one of the most important activities in daily life. This makes legibility a highly important area of concern. However, different letters have various levels of contrast, and there is still scholarly debate on how legibility should be defined. This paper discusses the literature on contrast and reading, with a particular focus on human contrast sensitivity. More specifically, this includes a review of previous studies on retinal spatial frequency, contrast sensitivity, object frequency bands that contribute to character recognition, and the effects of both character size and contrast on reading efficiency. Results show that the critical band of a letter and contrast sensitivity at the retinal spatial frequency at which the critical band is processed may help to predict reading efficiency. There are also several prospects for examining reading performance in individuals with low vision.

Author(s): Madoka Ohnishi

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