Light Therapy for University Students

Effects of Light Therapy on Well-being of University Students: A Pilot Study

The effects of light therapy on well-being among university students was investigated. A three-week intervention study examined whether the use of light glasses improved sleep quality and concentration and reduced symptoms of depression and anxiety among university students. First, a questionnaire was administered to about 130 students to screen for sleep problems. Based on the responses, those with the most sleep problems were invited to participate in the intervention study, which resulted in 39 participants in total. Although studies of light therapy for sleep problems and depression among patients have yielded positive results, the use of light has not been studied much among healthy individuals. The intervention study used glasses that project light in two intensities and participants were randomized into two groups with different intensities of light. The aim of the study was to: a) compare the effects of different light intensities on sleep and concentration and b) investigate whether light therapy influences symptoms of depression and anxiety among university students. The study is expected to increase knowledge of light therapy among healthy individuals, and if the treatment proves successful, it is an easy and inexpensive way to increase well-being among university students.

Study Overview

• Status: Completed
• Conditions: Well-being; Sleep Problems; University Students; Concentration Performance; Depression and Anxiety Symptom
• Intervention / Treatment: Device: Light Glasses (Experimental); Device: Light Glasses (Comparison)

• Study Type: Interventional
• Enrollment (Actual): 39
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Iceland
  • Reykjavik, Iceland, 102
    • Department of Psychology, Reykjavík University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Being psychology students at Reykjavik University, Iceland
• Able to understand, read and write Icelandic
• At screening assessment prior to the intervention, demonstrating a score of three or above on any of the six items of the BIS scale, thereby including students who showed even mild symptoms of sleep problems

Exclusion Criteria:

• Not being psychology students at Reykjavik University, Iceland
• Not able to understand, read and write Icelandic
• Demonstrating a score below three on all of the six items of the BIS scale

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Blue Light Therapy; Exposure of experimental circadian-effective blue light (BL) by glasses for 30 minutes each morning during the 3-week intervention	Device: Light Glasses (Experimental); The circadian-effective light glasses used by the experimental group (BL) emitted narrowband (peak lambda = 470 nm) blue light with an irradiance of 250 μW/cm2 (120 lux). The light glasses emit light from LEDs at a distance of 15 millimeters (15mm, 0.015.) from the eye. The device is classified as safe for the eyes in accordance with the international standard IEC 62471 and complies with the United States of America's FCC marking, and is designed to be worn on the participant's head, similar to a pair of glasses. For safety purposes, the light glasses do not contain UV or infra-red light. Brand: AYO glasses.
Active Comparator: Dim Light Therapy; Exposure of experimental comparison cirdadian-ineffective dim light (DL) by glasses for 30 minutes each morning during the 3-week intervention	Device: Light Glasses (Comparison); The circadian-ineffective sham glasses (DL) emitted blue light with an irradiance of 2.5 μW/cm2 (1.16 lux). The light glasses emit light from LEDs at a distance of 15 millimeters (15mm, 0.015.) from the eye. The device is classified as safe for the eyes in accordance with the international standard IEC 62471 and complies with the United States of America's FCC marking, and is designed to be worn on the participant's head, similar to a pair of glasses. For safety purposes, the light glasses do not contain UV or infra-red light. Brand: AYO glasses.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Bergen Insomnia Scale (BIS)	The Bergen Insomnia Scale (BIS) is a short scale on sleep habits consisting of six items pertaining to sleep onset, maintenance, early morning wakening, restorative sleep, daytime functioning, and sleep satisfaction. Responses indicate how often sleep problems, according to the six items, are experienced during the last month on an 8-point scale (0-7 days per week) with a range between 0 and 42, where a higher score suggests more sleep problems.	BIS was used to screen for sleep-related problems, prior to the intervention, at baseline (day 1), at the middle of intervention (FU1, day 11) and at the of intervention (FU2, day 21).
The Pittsburgh Sleep Quality Index (PSQI)	The Pittsburgh Sleep Quality Index (PSQI) consists of 19 self-rated items about sleep habits during the last month. The questions are categorised into seven components, rated from 0 to 3, evaluating sleep duration, quality, and latency as well as habitual sleep efficiency, sleep disturbances, usage of sleep medication, and daytime dysfunction. A global PSQI score, ranging from 0 to 21, is calculated by summarising the seven components' scores, where a higher global score indicates worse sleep quality and a score above five suggests poor sleep quality.	PSQI was administered at baseline (day 1), FU1 (day 11), and FU2 (day 21).
Objective sleep measure by actigraphy: Total time in bed	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Total time in bed, measured as minutes.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).
Objective sleep measure by actigraphy: Total sleep time	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Total sleep time, measured as minutes.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).
Objective sleep measure by actigraphy: Sleep latency	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Sleep latency, measured as minutes.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).
Objective sleep measure by actigraphy: Wake after sleep onset	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Wake after sleep onset, measured as minutes.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).
Objective sleep measure by actigraphy: Number of awakenings	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Number of awakenings, measured as number of awakenings per sleep period.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).
Objective sleep measure by actigraphy: Sleep fragmentation index	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Sleep fragmentation index, measured as percentage.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).
Objective sleep measure by actigraphy: Sleep movement index	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Sleep movement index, measured as events per hour.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).
Objective sleep measure by actigraphy: Sleep efficiency	Wrist-worn actigraphy devices (model GT3X+ ActiSleep) were used to objectively measure sleep. Sleep parameters were calculated using the Cole-Kripke sleep algorithm in the ActiLife 6 data analysis software. Parameter measured: Sleep efficiency, measured as percentage.	Participants were asked to wear the devices on their non-dominant arm for four consecutive days, both at baseline (day 1-4) and at FU2 (day 18-21).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Center for Epidemiological Studies Depression Scale (CES-D)	The Center for Epidemiological Studies Depression Scale (CES-D) is a 20 item self-report instrument, designed to measure common symptoms of depression that have occurred over the past week such as poor appetite, hopelessness, pessimism, and fatigue. Response options range from 0 to 3 for each item. Scores range from 0 to 60, with high scores indicating greater depressive symptoms.	CES-D was administered at baseline (day 1), FU1 (day 11) and FU2 (day 21).
General Anxiety Disorder (GAD-7)	General Anxiety Disorder (GAD-7) is a shorter version of the original GAD-13 item scale designed to measure anxiety. Each of the seven questions is rated on a 4-point Likert scale based on symptom frequency. The total score is calculated by summing the scores for all seven items, thus scores range from 0 to 21, with higer score meaning more anxiety. Cut-points are as follows: 0-4: Minimal anxiety, 5-9: Mild anxiety, 10-14: Moderate anxiety, and 15-21: Severe anxiety. A score of 10 or greater is often used as a clinical cut-off point.	GAD-7 was administered at baseline (day 1), FU1 (day 11) and FU2 (day 21).
The reduced Horne & Östberg Morningness-Eveningness Questionnaire (rMEQ)	The reduced Horne & Östberg Morningness-Eveningness Questionnaire (rMEQ) is a self-report questionnaire is one of the most widely used questionnaire to measure chronotype. The rMEQ consists of 5 questions that assess an individual's preference for morning or evening activities. Based on results from the scoring, individuals can be categorized as: Morning Types: Prefer morning activities; Evening Types: Prefer evening activities or Intermediate Types: Have no strong preference.	rMEQ was administered at baseline (day 1).
The Epworth Sleepiness Scale (ESS)	The Epworth Sleepiness Scale (ESS) is widely used in sleep research and clinical settings and consists of 8 questions (each with 4 answering possibilities) about sleepiness. measure a person's likelihood of dozing off during various daily activities. ESS provides a score ranging from 0 to 24, with higher scores indicating excessive daytime sleepiness. In general ESS scores can be interpreted as follows: 0-5 Lower Normal Daytime Sleepiness; 6-10 Higher Normal Daytime Sleepiness; 11-12 Mild Excessive Daytime Sleepiness; 13-15 Moderate Excessive Daytime Sleepiness; and 16-24 Severe Excessive Daytime Sleepiness.	ESS was administered at baseline (day 1), FU1 (day 11) and FU2 (day 21).
Objective measures of cognitive performance: Operation Span (Ospan)	Three neuropsychological tests were used to measure cognitive performance: Operation Span (Ospan) is a cognitive task designed to measure working memory capacity by requiring participants to remember sequences of letters while simultaneously solving simple math problems. This dual-task approach assesses how well individuals can manage their memory resources under distraction.	Ospan was administered at baseline (day 1) and FU2 (day 21).
Objective measures of cognitive performance: Digit span forward	Three neuropsychological tests were used to measure cognitive performance: Digit span forward is a cognitive task where a person listens to a sequence of numbers and then repeats them back in the same order. This task primarily measures short-term auditory memory and is commonly used in psychological assessments to evaluate working memory capacity.	Digit span forward was administered at baseline (day 1) and FU2 (day 21).
Objective measures of cognitive performance: Digit span backward	Three neuropsychological tests were used to measure cognitive performance: Digit span backward is a cognitive task that measures short-term memory by requiring participants to recall a sequence of numbers in reverse order. This task is more challenging than recalling the numbers in the original order, as it involves both storage and manipulation of the information.	Digit span backward was administered at baseline (day 1) and FU2 (day 21).

Collaborators and Investigators

• Sponsor: Reykjavik University
• Collaborators: The Icelandic Research Fund
• Investigators: Principal Investigator: Birna Baldursdottir, PhD, Reykjavík University, Iceland

Publications and helpful links

General Publications

• Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989 May;28(2):193-213. doi: 10.1016/0165-1781(89)90047-4.
• Spitzer RL, Kroenke K, Williams JB, Lowe B. A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med. 2006 May 22;166(10):1092-7. doi: 10.1001/archinte.166.10.1092.
• Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep. 1991 Dec;14(6):540-5. doi: 10.1093/sleep/14.6.540.
• Pallesen S, Bjorvatn B, Nordhus IH, Sivertsen B, Hjornevik M, Morin CM. A new scale for measuring insomnia: the Bergen Insomnia Scale. Percept Mot Skills. 2008 Dec;107(3):691-706. doi: 10.2466/pms.107.3.691-706.
• Radloff, L. S. (1977). The CES-D Scale: A Self-Report Depression Scale for Research in the General Population. Applied Psychological Measurement, 1(3), 385-401. doi:10.1177/014662167700100306
• Danielsson K, Sakarya A, Jansson-Frojmark M. The reduced Morningness-Eveningness Questionnaire: Psychometric properties and related factors in a young Swedish population. Chronobiol Int. 2019 Apr;36(4):530-540. doi: 10.1080/07420528.2018.1564322. Epub 2019 Jan 7.

Study record dates

Study Major Dates

• Study Start (Actual): March 6, 2019
• Primary Completion (Actual): April 8, 2019
• Study Completion (Actual): April 8, 2019

Study Registration Dates

• First Submitted: May 29, 2026
• First Submitted That Met QC Criteria: June 15, 2026
• First Posted (Actual): June 22, 2026

Study Record Updates

• Last Update Posted (Actual): June 22, 2026
• Last Update Submitted That Met QC Criteria: June 15, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Sleep; Intervention; Well-being; Young adults; Light therapy; University students
• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Behavioral Symptoms; Sleep Wake Disorders; Behavior; Anxiety Disorders; Parasomnias; Depression
• Other Study ID Numbers: VSN-19054

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: IPD will be shared upon reasoned requests.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No