{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,2]],"date-time":"2026-03-02T15:23:32Z","timestamp":1772465012230,"version":"3.50.1"},"reference-count":52,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T00:00:00Z","timestamp":1760400000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Bacground\/Objectives: This study aimed to develop age- and sex-specific spherical equivalent (SE) percentile curves and estimate the prevalence of refractive errors (REs) in Portuguese schoolchildren aged 6\u201317 years. Methods: A cross-sectional study was conducted in three schools in Lisbon, including 2205 children (mean age = 9.3 \u00b1 2.6 years; 49.3% boys). Vision was assessed using non-cycloplegic static retinoscopy (chosen due to feasibility in school settings) and visual acuity tests. SE percentile curves (P5\u2013P95) were generated by age and sex. SE values and RE distribution (hyperopia, emmetropia, and myopia) were compared across four age groups (6\u20138, 9\u201311, 12\u201314, and 15\u201317 years). Results: SE values decreased significantly with age (p &lt; 0.001). Median SE ranged from +0.50 D (6\u20138 years) to 0.00 D (15\u201317 years), with no sex differences. Hyperopia predominated in younger children (60.6% at 6\u20138 years), whereas myopia increased in older ages (32.2% at 15\u201317 years). Conclusions: This study presents the first SE percentile curves for Portuguese schoolchildren, providing a practical, age-specific reference for vision screening. The progressive shift from hyperopia to myopia highlights the importance of early detection and monitoring to prevent visual impairment.<\/jats:p>","DOI":"10.3390\/jcm14207262","type":"journal-article","created":{"date-parts":[[2025,10,15]],"date-time":"2025-10-15T11:57:42Z","timestamp":1760529462000},"page":"7262","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Spherical Equivalent Percentile Curves in a Portuguese School-Aged Population"],"prefix":"10.3390","volume":"14","author":[{"given":"Mar\u00eda Ibeth","family":"Pe\u00f1aloza-Barbosa","sequence":"first","affiliation":[{"name":"School for Doctoral Studies and Research, Universidad Europea de Madrid, 28670 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0996-5007","authenticated-orcid":false,"given":"Clara","family":"Martinez-Perez","sequence":"additional","affiliation":[{"name":"Instituto Superior de Educa\u00e7\u00e3o e Ci\u00eancias de Lisboa (ISEC Lisboa), Alameda das Linhas de Torres, 179, 1750-142 Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7558-4325","authenticated-orcid":false,"given":"Cristina","family":"Andreu-V\u00e1zquez","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, 28670 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2583-1789","authenticated-orcid":false,"given":"Miguel \u00c1ngel","family":"S\u00e1nchez-Tena","sequence":"additional","affiliation":[{"name":"Instituto Superior de Educa\u00e7\u00e3o e Ci\u00eancias de Lisboa (ISEC Lisboa), Alameda das Linhas de Torres, 179, 1750-142 Lisboa, Portugal"},{"name":"Department of Optometry and Vision, Faculty of Optics and Optometry, Universidad Complutense de Madrid, 28037 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1097-4581","authenticated-orcid":false,"given":"Cristina","family":"Alvarez-Peregrina","sequence":"additional","affiliation":[{"name":"Department of Optometry and Vision, Faculty of Optics and Optometry, Universidad Complutense de Madrid, 28037 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1045","DOI":"10.1007\/s00417-019-04290-6","article-title":"Growth curves of myopia-related parameters to clinically monitor the refractive development in Chinese schoolchildren","volume":"257","author":"Yang","year":"2019","journal-title":"Graefes Arch. 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