VISUAL REQUIREMENTS FOR READING

被引:296
作者
WHITTAKER, SG
LOVIEKITCHIN, J
机构
[1] Pennsylvania College of Optometry, Philadelphia, PA
[2] School of Optometry, Queensland University of Technology, Brisbane, QLD
关键词
READING; LOW VISION; VISUAL PSYCHOPHYSICS; VISUAL ACUITY; PRINT SIZE; CONTRAST SENSITIVITY; PRINT CONTRAST; FIELD OF VIEW; VISUAL FIELDS; SCOTOMA; MACULOPATHY; MACULAR DEGENERATION; RETINAL DISEASE;
D O I
10.1097/00006324-199301000-00010
中图分类号
R77 [眼科学];
学科分类号
100212 ;
摘要
We have applied research on the visual psychophysics of reading to low vision assessment. Research on different aspects of the reading process found that reading rate rather than reading comprehension is more sensitive to variations in a subject's visual functioning or the stimulus properties of print. The research identified four different visual factors that significantly affect reading rate: (1) acuity reserve [print size relative to acuity threshold], (2) contrast reserve [print contrast relative to contrast threshold], (3) field of view [number of letters visible], and (4) in cases of maculopathy, central scotoma size. Our research indicates that fluent reading rates can be attained with a restricted field of view, as little as four characters. However, attainment of fluent reading levels requires that print size and contrast should be several times threshold and the diameter of a central scotoma should be less than 22-degrees. Although important clinical studies are lacking, we derived specific visual requirements for different reading rates from published experimental research to provide a starting point and to illustrate how visual requirements could be derived, even with poor correlations. Research has made significant progress toward the development of a comprehensive low vision assessment that will allow the practitioner to identify visual impediments to reading, other than reduced visual acuity. Having more fully characterized a visual impairment, the practitioner may tailor devices or interventions to the individual's needs and capabilities.
引用
收藏
页码:54 / 65
页数:12
相关论文
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