2010 Volume 31 Issue 1 Pages 19-25
Purpose: In psychophysics, it is said that logarithmic (Log) visual acuity (VA) can be illustrated by normal distribution. We developed a statistical method for evaluating VA changes in an individual.
Methods and Results: LogVA and standard deviation (SD) were calculated by logistic regression. We assessed the change in VA using the χ2-test. We tested 1 individual with no visual abnormalities in order to assess the accuracy of this statistical evaluation method. LogVA was 0.368±0.021 in complete refractive correction and 0.243±0.016 in +0.50D incomplete refractive correction. We statistically evaluated the decrease in VA.
Conclusion: Heretofore, change in VA had not been assessed on a scientific basis in an individual. However, we calculated LogVA±SD by logistic regression and evaluated it using Nagai’s test of significant difference.
