Chief & Presenting Author: Dr.Sqn Ldr (Dr). Sridhara Reddy

Abstract

Introduction:Ishihara plate test is commonly used for screening and detection of colour vision defects . The studies carried among colour normals reports 10 to 15% of false positive errors.Identification of plates having a high probability of error reading could prevent an incorrect assessment.The study proposes quantitative assessment of reading difficulty in Ishihara charts in colour normals and predicts acceptable atypical errors
Method:A total of 380 participants in the age group of 16 to 25 years tested for colour vision with Martin Lantern, Fansworth D-15 and 38 plate Ishihara chart
Results:256 (67.36%) of colour normals read all plates without any error whereas 124 (32.63%) made errors. The distribution pattern of error scores is 78 participants made 1error,42 participants made 2 errors and 4 participants made 4errors
Conclusion:The first 25 plates have different probabilities of eliciting a correct response. The consideration of probability error scores is highly significant