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Sleep Onset LatencyCLEARNCT07391852

Circadian Light Exposure Adjustment for Restfulness

A study testing Amber Tinted Glasses, Clear Glasses and Smart Lightbulbs in people with Sleep Onset Latency, run by University of Arizona at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

Many young children are exposed to light int he evening hours before bedtime. Children's biological clocks are highly sensitive to evening light exposure, which can delay the timing of the clock and make it harder to fall asleep. Read more about this study

Who is it for?
Ages 60 to 83 months
Conditions the study is for
Sleep Onset Latency
What is being tested?
Amber Tinted Glasses, Clear Glasses and Smart Lightbulbs
Type of treatment
Medical device
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
60 participants
Where
1 siteUnited States
Study dates
29 Jan 2026to 31 Mar 2030
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 60 to 83 months
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • Inclusion requires that children are aged 5.0-6.9 years at the time of enrollment with a parent-reported sleep onset of ≥ 60 min after parents' desired bedtime at least three nights per week.
  • One adult parent of each participating child will also take part in the study. Parents must be able to provide consent for themselves and their child and to complete the interview at the end of the study.

Who cannot join

  • Children are excluded for the following reasons:
  • All sleep disorders as indicated on the telephone screener or by clinical cut-off scores on the Children's Sleep Habits Questionnaire (CSHQ), except for insomnia or DSWPD as features of these disorders are directly targeted by the intervention. Secondary analyses will explore if outcomes differ among participants with or without parent-reported symptoms consistent with these diagnoses.
  • Physical abilities that interfere with assessments (e.g., visual impairment), developmental disabilities (e.g., autism, attention-deficit/hyperactivity disorder (ADHD), pervasive developmental disorder), epilepsy or other neurological disorders, metabolic disorders, medical conditions that commonly require treatments or assessments during the night (e.g., cancer, diabetes, active asthma), current infection or lead poisoning; a head injury involving loss of consciousness in the past 6 months.
  • Current use of medications affecting daytime sleepiness, the circadian system, or light sensitivity.
  • Eye disorders or color blindness (determined with Ishihara Color Vision Test); corrected vision with eyeglasses is permitted.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Lauren E Hartstein, PhD contact

520-621-1360

laurenhartstein@arizona.edu

United States1 site, 1 recruiting
  • University of Arizona

    Tucson, Arizona, 85724

    Lauren E Hartstein, PhD, 520-621-1360, laurenhartstein@arizona.edu

    Recruiting

Other trials in United States

About this study

Many young children are exposed to light int he evening hours before bedtime. Children's biological clocks are highly sensitive to evening light exposure, which can delay the timing of the clock and make it harder to fall asleep. The purpose of this study is to test three strategies (adjustment to home lighting, amber-tinted glasses, clear glasses) to reduce evening light exposure in children ages 5-6 years with parent-reported sleep onset difficulties in order to improve their sleep and the timing of their biological clock. This study takes place over approximately 5 weeks. After baseline assessments of children's sleep timing, light exposure, cognition, and circadian rhythms, they will be randomly assigned to one of three interventions to reduce evening light exposure for two weeks. After the two-week intervention period, the baseline measures are repeated and parents are interviewed about their and their child's experiences with the intervention.

Read the detailed description

Evening sleep difficulties are common in young children and can contribute to behavioral and health problems. Sleep timing is regulated in part by the circadian clock, which is highly sensitive to light exposure. Light in the hour before bedtime can suppress melatonin, delay circadian timing, and make it harder for children to fall asleep. Despite evidence of high circadian sensitivity to evening light, few studies have tested interventions to improve sleep timing in early childhood using light-based strategies.

This study evaluates the feasibility, acceptability, and preliminary efficacy of two light-mitigation strategies to advance sleep and circadian timing in children aged 5 to 6 years with parent-reported sleep onset difficulties. Children will participate in a five-week study consisting of baseline assessments, a two-week intervention period, and post-intervention assessments. Parents of enrolled children will provide written informed consent for their child's participation. Children are under age 7 years and are not required to provide formal assent.

Baseline assessments will include sleep timing, duration, and quality measured via actigraphy, circadian phase assessed with salivary dim-light melatonin onset (DLMO), parent-reported sleep behaviors, and a cognitive battery. Children will then be randomly assigned to one of three interventions: (1) smart home lighting to reduce evening short-wavelength light, (2) amber-tinted glasses worn in the hour before bedtime, or (3) clear glasses as a sham control. Interventions will last two weeks, with adherence monitored throughout.

After the intervention, all assessments will be repeated, and parents will participate in structured interviews to report on the feasibility and acceptability of the assigned strategy. Exploratory measures will include baseline pupillary light response to examine individual differences in photosensitivity as potential moderators of intervention effects.

Data from this study will inform the feasibility and acceptability of light-based interventions in young children (Aim 1), provide preliminary evidence of effects on sleep and circadian timing (Aim 2), and explore whether photosensitivity moderates response to the interventions (Exploratory Aim 3).

Being tested
Amber Tinted Glasses, Clear Glasses, Smart Lightbulbs
Keywords
Behavioral sleep problems, Circadian phase, sleep onset latency, Early childhood, dim light melatonin onset (DLMO), Evening light exposure, Light intervention

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Amber Tinted GlassesDevice

    Children will wear amber-tinted glasses in the evening hours before bedtime to reduce exposure to short-wavelength (blue) light. The glasses are intended to reduce circadian disruption associated with evening light exposure.

  • Clear GlassesDevice

    Children will wear clear glasses in the evening hours before bedtime. This sham intervention controls for wearing glasses without reducing light exposure.

  • Smart LightbulbsDevice

    Smart light bulbs will be installed in the child's home and programmed to reduce short-wavelength light exposure during evening hours before bedtime.

Study groups in NCT07391852
Study groupRoleWhat they receive
Amber Tinted GlassesExperimentalWearing "blue-blocker" glasses (lenses that filter out the blue portion of the visible spectrum) can reduce the melatonin suppression and alertness effects of evening light exposure in both adults and adolescents, as well as advance the timing of the circadian clock and sleep onset, compared with participants wearing placebo lenses. This intervention will examine their efficacy in advancing young children's sleep and circadian timing. Children will be given a pair of glasses (Block Blue Light), with amber-tinted lenses (advertised as blocking 100% of light from 380-550 nm. Children will wear the glasses starting 1 h before parent's selected bedtime each evening across the two-week intervention. Parents will also complete a daily diary detailing when the glasses are worn.
Receives: Device: Amber Tinted Glasses
Clear GlassesSham comparatorThe sham comparator consists of the same protocols for the amber-tinted glasses, except that children will wear a pair of glasses with clear lenses (advertised as blocking 50% of light from 400-500 nm), which are significantly less effective at blocking short-wavelength light.
Receives: Device: Clear Glasses
Smart LightbulbsExperimentalThe presence of more blue light in the home is associated with later circadian timing in both school-aged children and adults. This intervention will adjust the evening home lighting environment to be less stimulating to children's circadian clocks. Smart light bulbs (dimmable and color tunable LED bulbs) will be installed in participants' homes light fixtures, or in the child's bedroom, bathroom, as well as areas the child is likely to spend time in after dinner (i.e., living room, playroom). The researchers will program the lights to transition to a lower CCT and dimmer intensity to achieve the recommended evening mEDI of 10 lux starting 1 h before the child's parent-selected bedtime.
Receives: Device: Smart Lightbulbs

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Intervention Feasibility

    Feasibility will be assessed using adherence/compliance rates to assigned intervention protocols.

    Measured: Throughout the two-week intervention period.

  2. Acceptability

    Acceptability will be assessed using parent-reported qualitative interviews conducted post-intervention.

    Measured: Week 5

Secondary outcomes (4)
  1. Circadian Timing

    Dim light melatonin onset, a measure of circadian timing, will be assessed via saliva samples.

    Measured: Assessed once in Week 2 and once in Week 5

  2. Sleep Timing

    Throughout the duration of the study, the child will wear a wrist actigraph which records sleep timing and light exposure. The actigraph is a watch-size monitor worn on the non-dominant wrist, providing continuous imputation of sleep-wake states via arm activity. These data will be used to examine changes in habitual sleep timing, sleep onset latency.

    Measured: Throughout the 5 week protocol

  3. Light Exposure

    Measured by the wrist-worn actigraph watch in 1-min epochs throughout data collection. These data provide an objective measure of the child's light exposure throughout the protocol (including compliance with the home lighting intervention) and will be used to examine changes in habitual light exposure.

    Measured: Throughout the 5 week protocol.

  4. Sleep-Related Behaviors

    Change in parent-reported sleep behaviors assessed via validated questionnaires.

    Measured: Assessed once in Week 1 and once in Week 5

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 Feb 2026
  2. Study start29 Jan 2026
  3. Primary completion31 Dec 2029 (estimated)
  4. Study completion31 Mar 2030 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
60 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07391852
Sponsor's protocol ID
STUDY00005764: CLEAR
Other IDs
K01HL181331
Acronym
CLEAR
Status last verified
Jul 2026
First submitted
7 Jan 2026
Last updated
14 Oct 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: No identifiable data will be shared. Only de-identified study data will be made available for research purposes.

Publications

  • Werner H, Lebourgeois MK, Geiger A, Jenni OG. Assessment of chronotype in four- to eleven-year-old children: reliability and validity of the Children's Chronotype Questionnaire (CCTQ). Chronobiol Int. 2009 Jul;26(5):992-1014. doi: 10.1080/07420520903044505.

    PubMed 19637055
  • LeBourgeois MK, Harsh JR. Development and psychometric evaluation of the Children's Sleep-Wake Scale<sup/> Sleep Health. 2016 Sep;2(3):198-204. doi: 10.1016/j.sleh.2016.04.001.

    PubMed 28066802
  • Zerbini G, Kantermann T, Merrow M. Strategies to decrease social jetlag: Reducing evening blue light advances sleep and melatonin. Eur J Neurosci. 2020 Jun;51(12):2355-2366. doi: 10.1111/ejn.14293. Epub 2018 Dec 13.

    PubMed 30506899
  • van der Lely S, Frey S, Garbazza C, Wirz-Justice A, Jenni OG, Steiner R, Wolf S, Cajochen C, Bromundt V, Schmidt C. Blue blocker glasses as a countermeasure for alerting effects of evening light-emitting diode screen exposure in male teenagers. J Adolesc Health. 2015 Jan;56(1):113-9. doi: 10.1016/j.jadohealth.2014.08.002. Epub 2014 Oct 3.

    PubMed 25287985
  • Owens JA, Spirito A, McGuinn M. The Children's Sleep Habits Questionnaire (CSHQ): psychometric properties of a survey instrument for school-aged children. Sleep. 2000 Dec 15;23(8):1043-51.

    PubMed 11145319
  • Lebourgeois MK, Wright KP Jr, Lebourgeois HB, Jenni OG. Dissonance Between Parent-Selected Bedtimes and Young Children's Circadian Physiology Influences Nighttime Settling Difficulties. Mind Brain Educ. 2013 Dec;7(4):234-242. doi: 10.1111/mbe.12032.

    PubMed 24535929
  • Hartstein LE, Wong SD, Abbas L, Choubai S, Wilson JN, Jablin T, LeBourgeois MK. Creating the Cave: Conducting Circadian Science in Early Childhood. Clocks Sleep. 2023 Feb 20;5(1):85-93. doi: 10.3390/clockssleep5010009.

    PubMed 36810846
  • Hartstein LE, Diniz Behn C, Wright KP Jr, Akacem LD, Stowe SR, LeBourgeois MK. Evening Light Intensity and Phase Delay of the Circadian Clock in Early Childhood. J Biol Rhythms. 2023 Feb;38(1):77-86. doi: 10.1177/07487304221134330. Epub 2022 Nov 22.

    PubMed 36415902
  • Hartstein LE, Behn CD, Akacem LD, Stack N, Wright KP Jr, LeBourgeois MK. High sensitivity of melatonin suppression response to evening light in preschool-aged children. J Pineal Res. 2022 Mar;72(2):e12780. doi: 10.1111/jpi.12780. Epub 2022 Jan 8.

    PubMed 34997782

Questions about this trial

What is this clinical trial studying?

A study testing Amber Tinted Glasses, Clear Glasses and Smart Lightbulbs in people with Sleep Onset Latency, run by University of Arizona at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 14 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Lauren E Hartstein, PhD (520-621-1360, laurenhartstein@arizona.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Intervention Feasibility (time frame: Throughout the two-week intervention period.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07391852, which also lists 9 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Oct 2026.

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