Circadian Light Exposure Adjustment for Restfulness

NCT07391852 | Not Yet Recruiting DMC

• 2 other identifiers: STUDY00005764: CLEARK01HL181331
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Sleep Onset Latency

Keywords

Behavioral sleep problems; Circadian phase; sleep onset latency; Early childhood; dim light melatonin onset (DLMO); Evening light exposure; Light intervention

Outcome Measures

Primary Outcomes (2)

• Intervention Feasibility

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

  Throughout the two-week intervention period.

• Acceptability

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

  Week 5

Secondary Outcomes (4)

• Circadian Timing

  Assessed once in Week 2 and once in Week 5

• Sleep Timing

  Throughout the 5 week protocol

• Light Exposure

  Throughout the 5 week protocol.

• Sleep-Related Behaviors

  Assessed once in Week 1 and once in Week 5

Other Outcomes (2)

• Pupillary Light Response

  Baseline

• Cognitive Functioning

  Assessed once in Week 1 and once in Week 5

Study Arms (3)

Amber Tinted Glasses

EXPERIMENTAL

Wearing "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.

Device: Amber Tinted Glasses

Clear Glasses

SHAM COMPARATOR

The 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.

Device: Clear Glasses

Smart Lightbulbs

EXPERIMENTAL

The 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.

Device: Smart Lightbulbs

Interventions

Amber Tinted Glasses DEVICE

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.

Amber Tinted Glasses

Clear Glasses DEVICE

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

Clear Glasses

Smart Lightbulbs DEVICE

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

Smart Lightbulbs

Eligibility Criteria

• Age: 60 Months - 83 Months
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• University of Arizona: lead
• National Heart, Lung, and Blood Institute (NHLBI): collaborator

Study Sites (1)

University of Arizona

Tucson, Arizona, 85724, United States

Location

Related Publications (9)

• 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.

  PMID: 19637055 BACKGROUND

• 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.

  PMID: 28066802 BACKGROUND

• 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.

  PMID: 30506899 BACKGROUND

• 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.

  PMID: 25287985 BACKGROUND

• 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.

  PMID: 11145319 BACKGROUND

• 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.

  PMID: 24535929 BACKGROUND

• 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.

  PMID: 36810846 BACKGROUND

• 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.

  PMID: 36415902 BACKGROUND

• 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.

  PMID: 34997782 BACKGROUND

Study Officials

• Lauren E Hartstein, PhD

  University of Arizona

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Lauren E Hartstein, PhD

CONTACT

520-621-1360; laurenhartstein@arizona.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants are blinded to study condition. Research staff are aware of assignment after baseline assessments. Laboratory technicians conducting melatonin assays are blinded to study hypotheses and participant condition.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 7, 2026
• First Posted: February 6, 2026
• Study Start: January 15, 2026
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): July 31, 2030
• Last Updated: February 6, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)