Carpena Torres, CarlosBatres Valderas, LauraSerramito Blanco, MaríaCarracedo Rodríguez, Juan Gonzalo2025-01-092025-01-092024-07-02Carpena-Torres, C.; Batres, L.; Serramito, M.; Carracedo, G. Repeatability of Subjective Refraction in Different Age Groups. Photonics 2024, 11, 634. https://doi.org/10.3390/photonics1107063410.3390/photonics11070634https://hdl.handle.net/20.500.14352/113531Background: The purpose of this study was to assess the inter-examiner repeatability of subjective refraction across diverse age cohorts, an aspect not previously investigated. Methods: A cross-sectional, randomized study enrolled 86 participants (mean age: 37.0 ± 18.0 years), distributed into three groups: youth, non-presbyopic adults, and presbyopic adults. Each participant underwent three subjective refractions by three different optometrists on separate days. Repeatability analysis encompassed all refractive variables (M, J0, and J45). Results: There were no significant differences between optometrists in all refractive variables for either the overall sample or across age groups (p ≥ 0.05). Additionally, no correlation was found between participants’ age and the mean difference in refractive variables across optometrists (p ≥ 0.05). The 95% confidence interval of repeatability (r) for the total sample was ±0.70 D for M, ±0.29 for J0, and ±0.21 D for J45. Conclusions: Based on these findings and previous research, it is suggested to establish 95% limits of agreement of ±0.75 D for M, and between ±0.25 D and ±0.50 D for both J0 and J45 when validating new refraction systems compared to subjective refraction as the gold standard, regardless of the age of the subjects evaluated.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/journal articlehttps://doi.org/10.3390/photonics11070634open access535.31RepeatabilitySubjective refractionAgeMyopiaHyperopiaAstigmatismÓptica y optometría2209 Óptica