The reliability of visual acuity scores yielded by three commercial devices

Abstract

The authors present a summary of an investigation of the reliability of the acuity scales of the Keystone "Telebinocular," the American Optical "Sight-Screener," the Bausch and Lomb "Ortho-Rater," and standard and modified Snellen type letters. Test-retest coefficients indicate that while the 3 instruments have somewhat higher reliability for determining remote acuity than standard Snellen letters, the improved Snellen-type lettering is slightly superior to all other tests used. Standard Snellen-type lettering gave the largest correlation ratios. The conclusion is reached that the lens systems used in the instruments for simulating distance may account for the lower instrument ratios. (PsycInfo Database Record (c) 2025 APA, all rights reserved)