{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T20:03:07Z","timestamp":1792180987522,"version":"4.4.0"},"reference-count":32,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,3,17]],"date-time":"2025-03-17T00:00:00Z","timestamp":1742169600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Grants-in-Aid for Scientific Research","award":["18K09424"],"award-info":[{"award-number":["18K09424"]}]},{"name":"Tsubota Laboratory, Inc.","award":["18K09424"],"award-info":[{"award-number":["18K09424"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>This study examines the role of violet light (VL) in preventing myopia progression, addressing a critical need in urban environments where VL exposure is limited. Recent research suggests that VL, within the 360\u2013400 nm wavelength range, may reduce myopia risk. To investigate, we conducted spectroscopic measurements in various settings across Tokyo, quantifying VL irradiance in natural sunlight. The results showed high VL levels outdoors, averaging 583 \u03bcW\/cm2 on sunny days and 271 \u03bcW\/cm2 on cloudy days, leading to a weighted annual average of approximately 310 \u03bcW\/cm2. In contrast, indoor environments lacked VL due to UV-blocking materials in windows, glasses, and lighting. This deficiency may contribute to the rising incidence of myopia, particularly in urban areas with reduced outdoor exposure. Our findings highlight the need for innovative solutions to mitigate VL deficiency indoors, such as optimizing architectural designs and artificial lighting to better incorporate VL. This study provides foundational insights for future interventions aimed at reducing myopia risk through improved indoor light environments.<\/jats:p>","DOI":"10.3390\/ijerph22030444","type":"journal-article","created":{"date-parts":[[2025,3,17]],"date-time":"2025-03-17T08:57:02Z","timestamp":1742201822000},"page":"444","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Violet Light Is Abundant Outdoors but Deficient Indoors in Modern Lifestyle in Tokyo"],"prefix":"10.3390","volume":"22","author":[{"given":"Shinichiro","family":"Kondo","sequence":"first","affiliation":[{"name":"Tsubota Laboratory, Inc., Tokyo 160-8582, Japan"},{"name":"Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3762-0054","authenticated-orcid":false,"given":"Xiaoyan","family":"Jiang","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9533-7404","authenticated-orcid":false,"given":"Hidemasa","family":"Torii","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan"},{"name":"Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kiwako","family":"Mori","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan"},{"name":"Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2892-9810","authenticated-orcid":false,"given":"Kazuno","family":"Negishi","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5457-2720","authenticated-orcid":false,"given":"Toshihide","family":"Kurihara","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan"},{"name":"Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8874-7111","authenticated-orcid":false,"given":"Kazuo","family":"Tsubota","sequence":"additional","affiliation":[{"name":"Tsubota Laboratory, Inc., Tokyo 160-8582, Japan"},{"name":"Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,17]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2017). 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