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Completed

NCT Number: NCT06310135

Filtered Eyewear to Prevent Light-induced Melatonin Suppression - Aim 1

The aim of this study is to determine the relative effectiveness of monocular and binocular light exposures, with and without selective blue-blocking filtering, on nocturnal melatonin suppression, subjective sleepiness, and visual performance of night shift workers.

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Key information

Conditions

Sleep Quality Dyssomnias Mental Disorders Nervous System Diseases Sleep Disorders, Intrinsic Sleep Initiation and Maintenance Disorders Sleep Wake Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Light and Health Research Center

Menands, New York, 12204, United States

About this study

Over the course of six, 5-hour study nights, 30 participants will be randomized to 6 study conditions, 1) binocular dim-light control unfiltered, (2) monocular dim-light control (one eye occluded), (3) unfiltered binocular, (4) unfiltered monocular (non-dominant eye occluded), (5) filtered binocular (both eyes filtered), (6) filtered monocular (non-dominant eye filtered, the other non-filtered). Saliva samples will be collected every 30 minutes for melatonin levels. Participants will also be asked to provide subjective sleepiness and visual performance will be assessed. Study nights will be separated by one week and each participant will be randomized to one of the six study conditions each night. All participants will see all conditions.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy

Exclusion criteria

  • Bipolar disorder
  • Seasonal depression
  • Diabetes
  • High blood pressure
  • History of cancer
  • Obstructing cataracts
  • Macular degeneration
  • Diabetic retinopathy
  • Glaucoma
  • Use of melatonin supplements
  • Use of beta blockers
  • Use of sleep medications
  • Use of antidepressant medication

Treatment and study plan

Filtered Eyewear

Device

Filtered binocular viewing condition will be produced by eyeglasses frames with orange-tinted blue-blocking filter, eliminating all optical radiation for wavelengths shorter than 540 nm. For the filtered monocular condition, only the lens on the eyeglasses frame on the non-dominant eye will be tinted with the blue-blocking filter.

Unfiltered Eyewear

Device

For the unfiltered binocular, the subjects will wear transparent eyeglasses frames with no optical power. Unfiltered monocular vision will be produced by an opaque eyepatch occluding the non-dominant eye.

No Filters

Other

Dim lights with no filters.

Primary outcomes

  1. Melatonin Levels AUC

    Time frame: Each night for 6 study nights

    Melatonin levels to assess Melatonin Suppression. Saliva samples will be collected every 30 minutes for melatonin levels.

Secondary outcomes

  1. Karolinska Sleepiness scale to measure Subjective Sleepiness

    Time frame: Each night for 6 study nights

    Subjective sleepiness will be measured using the Karolinska Sleepiness scale. This 9-point scale scores range from 1-9, where 1 = "very alert," 3 = "alert," 5 = "neither alert nor sleepy," 7 = "sleepy, but no difficulty remaining awake," and 9 = "very sleepy, fighting sleep, an effort to remain awake." Full scale from 1-9. A higher number indicates greater sleepiness.

  2. Numerical Verification Task (NVT)

    Time frame: Each night for 6 study nights

    The NVT requires participants to compare 2 lists of 20 pairs of 5-digit numerals at 2 contrasts (0.2 and 0.8), and the response time required to complete the task is recorded as the performance measure. A faster response time indicates better visual performance.

Sponsors and collaborators

Lead sponsor

Icahn School of Medicine at Mount Sinai

Other

Registry information

Official study title

Filtered Eyewear to Prevent Light-induced Melatonin Suppression While Maintaining Visual Performance and Alertness in Night-shift Working Nurses - Aim 1

Important dates

Study start
2024
Primary completion
2024
Study completion
2024
First posted
Mar 15, 2024
Registry last updated
Aug 5, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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