Retina-Friendly Phototherapeutic Light Source – Hypothesis, Formula and Device Fabrication

Retina-Friendly Phototherapeutic Light Source – Hypothesis, Formula and Device Fabrication | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Retina-Friendly Phototherapeutic Light Source – Hypothesis, Formula and Device Fabrication Wei-Zhu Lin, Che-Wei Chang, Ting-Hao Liu, Yong-Bin Guan, Jung-Chun Chih, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7618541/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Winter’s lack of sunshine often leads to seasonal affective disorder, and insufficient morning light exposure can likewise provoke insomnia or even precipitate depression. To address these issues, light therapy has been introduced. However, certain light-therapy protocols can cause ocular discomfort; in particular, overexposure to blue-rich white light is known to induce photoretinitis. Consequently, there is an urgent need for approaches that balance retinal safety with therapeutic efficacy. To date, no quantitative studies have tackled this dual requirement. Here, we propose a novel model that, under the constraint of retinal friendliness, maximizes the effectiveness of light therapy. Our model quantifies therapeutic efficacy via melatonin suppression sensitivity (MSS) and sets the retinal permissible exposure limit (MPE) as the upper bound on treatment duration. Under these parameters, a 6.5-hour light therapy session can achieve up to 79% of the maximal effect, requiring an illuminance of 2,240 lx. Alternatively, a 1.5-hour targeted treatment using 1,000 lx of 620 nm orange light yields 59% efficacy. Furthermore, continuous home illumination at 1,700 K for 6.5 hours produces 77% of the maximal therapeutic effect. Health sciences/Diseases Health sciences/Medical research Biological sciences/Neuroscience Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7618541","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":559845055,"identity":"b8050f25-1149-4182-92d4-f8858fccaf06","order_by":0,"name":"Wei-Zhu Lin","email":"","orcid":"","institution":"National Tsing Hua University","correspondingAuthor":false,"prefix":"","firstName":"Wei-Zhu","middleName":"","lastName":"Lin","suffix":""},{"id":559845056,"identity":"5f6ebba5-c425-4e9a-bfbc-ef450de4d66b","order_by":1,"name":"Che-Wei Chang","email":"","orcid":"","institution":"National Tsing Hua 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Jou","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyElEQVRIiWNgGAWjYBACxoYDDAwfwEweEMFMnBbGGSAWG0wLGxE2MfOQpIW58fAxaducwwzm8r3HJBgqrBMb5HsMCDjsWJp07rY0Bss2vjQJhjPpiQ1sPIS0nDEDarFhMDjGYybB2HYYqIV3A2EtltskoFr+EauFEW5LA1FajiVb9m5L4zE4lmNskXAs3biNLf8DXi2GMw4fvPFz22E5g8NnDG98qLGW7Wc+lkBAywEwDY4UBpBagjEpz99ASMkoGAWjYBSMeAAApqtAJ4uTbNkAAAAASUVORK5CYII=","orcid":"","institution":"National Tsing Hua University","correspondingAuthor":true,"prefix":"","firstName":"Jwo-Huei","middleName":"","lastName":"Jou","suffix":""}],"badges":[],"createdAt":"2025-09-15 09:08:35","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7618541/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7618541/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98346976,"identity":"5f35bc91-688f-49bb-bb65-0a0aa8d6799c","added_by":"auto","created_at":"2025-12-16 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To address these issues, light therapy has been introduced.\u003c/p\u003e \u003cp\u003eHowever, certain light-therapy protocols can cause ocular discomfort; in particular, overexposure to blue-rich white light is known to induce photoretinitis.\u003c/p\u003e \u003cp\u003eConsequently, there is an urgent need for approaches that balance retinal safety with therapeutic efficacy. To date, no quantitative studies have tackled this dual requirement.\u003c/p\u003e \u003cp\u003eHere, we propose a novel model that, under the constraint of retinal friendliness, maximizes the effectiveness of light therapy. Our model quantifies therapeutic efficacy via melatonin suppression sensitivity (MSS) and sets the retinal permissible exposure limit (MPE) as the upper bound on treatment duration. Under these parameters, a 6.5-hour light therapy session can achieve up to 79% of the maximal effect, requiring an illuminance of 2,240 lx. Alternatively, a 1.5-hour targeted treatment using 1,000 lx of 620 nm orange light yields 59% efficacy. 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