作者
Jason S Ng, Brian Shih
发表日期
2017/5
期刊
European journal of ophthalmology
卷号
27
期号
3
页码范围
363-366
出版商
SAGE Publications
简介
Purpose
Minimizing false-positives (FPs) when evaluating color vision is important in eye care. Identification of plate 1 (demonstration plate) is often considered a way to avoid FPs. However, few studies have quantified the minimum level of visual acuity (VA) that would minimize FPs for the Ishihara and HRR color tests.
Methods
Threshold levels of optical defocus were obtained from 25 color normal subjects. Blur levels were obtained for Ishihara (38 plate) plates 1, 10, and 15 and 4th edition HRR plates 1, 7, 10, and 20 using the method of limits. Corresponding VAs were measured through these blur levels at 40 centimeters after adjusting for the dioptric distance difference. Analysis of variance testing was used to analyze the data.
Results
Mean optical defocus values in diopters (mean ± SD) for HRR plates 1, 7, 10, and 20 were 6.23 ± 1.61, 1.23 ± 1.16, 2.41 ± 1.31, and 7.96 ± 2.03, respectively, and for Ishihara plates …
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Level of visual acuity necessary to avoid false-positives on the HRR and Ishihara color vision tests
JS Ng, B Shih - European journal of ophthalmology, 2017