Evaluation of A Modified Persian Version of the Developmental Eye Movement Test in Children

Purpose: To adapt and evaluate the Developmental Eye Movement (DEM) test in Persian for Iranian children aged 7-12 years, to evaluate developmental changes across ages, and to compare performance with the American normative sample to identify potential linguistic and cultural influences on oculomotor behavior. Methods: The DEM test was developed by translating the original numbers into Persian numerals. Awe enrolled a sample of 720 Iranian children aged 7-12 years utilizing a stratified random sampling method from four educational districts in Shiraz. The assessment was administered in accordance with the standardized protocol detailed in the official manual, except that the numerals were read from right to left. To evaluate test reliability, a subset of 160 children aged 8-9 years underwent retesting. Results: Administration of the DEM test revealed age-related improvements in oculomotor skill that reached a plateau around age 10. Iranian children were slower than the American normative sample on both vertical and horizontal tasks, produced higher ratios, and made more errors in most age groups. These differences had largely evened out by age 12, pointing to the influence of linguistic and orthographic factors. The test was highly reliable across repeated administrations (coefficients: 0.78-0.95). Conclusion: This study thus provides Persian-language normative data and supports the reliability of the DEM test for this population. This investigation successfully established Persianlanguage normative data for the DEM test and confirmed the instrument’s reliability within an Iranian population. In light of the substantial influence of cultural and linguistic factors on oculomotor behavior, these findings emphasize the critical need to utilize population-specific norms to ensure diagnostic accuracy and prevent the misclassification of typically developing readers.