The validity and reliability of heterophoria scores yielded by three commercial optical devices

Abstract

The Maddox rod test score was used as a criterion and compared with scores on the Ortho-Rater, the Sight Screener, and the Telebinocular. The following conclusions are made: (1) no one instrument for measuring heterophoria is preferable to the other two; (2) when administered only once, none of the tests offers sufficient reliability for fine scale measurements of lateral or vertical phoria; (3) the machines offer reliabilities as great as certain accepted clinical tests; (4) no decision can be reached regarding the validity of the 3 machines since there is not a satisfactory correlation with the criterion test used. (PsycInfo Database Record (c) 2025 APA, all rights reserved)