Smart Light Therapy Glasses for Sleep, Cognition, and Mental Wellness

dc.contributor.authorTang, Lucas
dc.date.accessioned2025-12-23T14:20:47Z
dc.date.available2025-12-23T14:20:47Z
dc.date.issued2025-12-23
dc.date.submitted2025-12-12
dc.description.abstractFor the past century, people have gradually transitioned to spending their time indoors where, compared with the outdoors, light levels are significantly lower during the day and higher at night. This mismatch of lighting has been associated with related health problems like rising depression rates and sleep issues. As such, bright-light therapy has been established as a treatment for mood and sleep disorders. However, existing devices face major barriers to adoption; light boxes require people to stay in one place for a long time, and wearable products often lack social acceptability. As a result, the research literature has been constrained to short interventions with limited exploration of dose, duration, and individualized understanding of response to light. This thesis presents the design, engineering, and clinical evaluation of a pair of smart light therapy glasses (Lumos glasses) developed to improve convenience, social acceptability, and comfort. The hardware provides the foundational infrastructure for an intelligent, data-driven approach to personalized circadian health. The glasses use a nanotechnology lens with wavelength-based reflection, which allows key light therapy components to be compacted into a classic glasses shape. A hardware-software platform was developed featuring calibrated light therapy optical systems, on-device sensors for reliable wear detection, melanopic ambient light detection, an FCC-approved Bluetooth module with a custom antenna, as well as a compatible cloud-connected mobile app. More than 100 units were manufactured and deployed in a double-blind, randomized, placebo-controlled crossover clinical trial. Participants receiving bright-light showed significant improvements in sleep disturbance (PROMIS) and psychomotor vigilance (PVT) relative to active dim-light control. Stratified analyses revealed that participants with darker eyes generally exhibited more significant improvements under bright-light compared to dim-light control. In contrast, mood (using the Montegomery Asberg Depression Rating Scale) and working memory (word-pair recall) reached statistical significance only after accounting for eye color. Exploratory models also showed that daily use and exposure to ambient light were correlated with improved outcomes, while higher baseline severity strongly predicted room for change. Age and sex contributed smaller, secondary effects. For working memory, dark-eyed participants showed significant Phase~1 gains under bright-light, while other subgroups demonstrated positive associations between daily usage and recall performance. This yielded meaningful insights that adherence and individual pigmentation influence optimal light dosage. This work demonstrates that mobile sensor-driven light therapy can overcome long-standing adherence barriers and enable in-depth research about dose–response and personalization. By combining engineering innovation with clinical validation, the Lumos Smart Glasses provide a foundation for next-generation circadian health technologies that are practical, effective, and scalable.
dc.identifier.urihttps://hdl.handle.net/10012/22784
dc.language.isoen
dc.pendingfalse
dc.publisherUniversity of Waterlooen
dc.subjectlight therapy
dc.subjectcircadian rhythm
dc.subjectsleep
dc.subjectmental health
dc.subjectdepression
dc.subjectwearable devices
dc.subjectsmart glasses
dc.subjectphotobiology
dc.subjectoptical engineering
dc.subjectmelanopsin
dc.subjectblue light
dc.subjectsleep quality
dc.subjectmood
dc.subjectcognitive performance
dc.subjectpsychomotor vigilance task
dc.subjectreaction time
dc.subjectmemory
dc.subjectclinical trial
dc.subjectrandomized controlled trial
dc.subjectcrossover study
dc.subjectadherence
dc.subjectreal-world data
dc.subjecteye pigmentation
dc.subjectindividual differences
dc.subjectcircadian-effective light
dc.subjectambient light exposure
dc.subjectseasonal affective disorder
dc.subjectnon-seasonal depression
dc.subjectwearable light therapy
dc.subjectphotobiological safety
dc.subjectIEC 62471
dc.titleSmart Light Therapy Glasses for Sleep, Cognition, and Mental Wellness
dc.typeMaster Thesis
uws-etd.degreeMaster of Applied Science
uws-etd.degree.departmentMechanical and Mechatronics Engineering
uws-etd.degree.disciplineMechanical Engineering
uws-etd.degree.grantorUniversity of Waterlooen
uws-etd.embargo.terms0
uws.contributor.advisorPan, Zhao
uws.contributor.affiliation1Faculty of Engineering
uws.peerReviewStatusUnrevieweden
uws.published.cityWaterlooen
uws.published.countryCanadaen
uws.published.provinceOntarioen
uws.scholarLevelGraduateen
uws.typeOfResourceTexten

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