NCT07391852 · University of Arizona
Circadian Light Exposure Adjustment for Restfulness
(CLEAR)
What this study is about
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.
View original scientific description
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.
Interventions
DEVICE
Amber Tinted Glasses
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.
DEVICE
Clear Glasses
Children will wear clear glasses in the evening hours before bedtime. This sham intervention controls for wearing glasses without reducing light exposure.
DEVICE
Smart Lightbulbs
Smart light bulbs will be installed in the child's home and programmed to reduce short-wavelength light exposure during evening hours before bedtime.
Primary outcome measures
Intervention Feasibility
Time frame: Throughout the two-week intervention period.
Feasibility will be assessed using adherence/compliance rates to assigned intervention protocols.
Acceptability
Time frame: Week 5
Acceptability will be assessed using parent-reported qualitative interviews conducted post-intervention.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Exclusion criteria
- 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.
Where
- Tucson, Arizona
Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 14, 2026 · Source of record for eligibility and locations