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

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

Study Overview

• Status: Completed
• Conditions: Sleep Quality
• Intervention / Treatment: Device: Unfiltered Eyewear; Device: Filtered Eyewear; Other: No Filters

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 29
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Menands, New York, United States, 12204
      • Light and Health Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Unfiltered Monocular; Unfiltered monocular with the non-dominant eye occluded.	Device: Unfiltered Eyewear; 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.
Experimental: Filtered Binocular; Filtered binocular with both eyes filtered.	Device: Filtered Eyewear; 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.
Experimental: Filtered Monocular; Filtered monocular with non-dominant eye filtered, the other non-filtered.	Device: Filtered Eyewear; 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.
Experimental: Unfiltered Binocular; Unfiltered binocular - neither eye will be filtered.	Device: Unfiltered Eyewear; 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.
Placebo Comparator: Dim Light Control; Dim light with no filters.	Other: No Filters; Dim lights with no filters.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Melatonin Levels AUC	Melatonin levels to assess Melatonin Suppression. Saliva samples will be collected every 30 minutes for melatonin levels.	Each night for 6 study nights

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Karolinska Sleepiness scale to measure Subjective Sleepiness	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.	Each night for 6 study nights
Numerical Verification Task (NVT)	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.	Each night for 6 study nights

Collaborators and Investigators

• Sponsor: Icahn School of Medicine at Mount Sinai
• Investigators: Principal Investigator: Mariana Figueiro, ICAHN School of Medicine at Mount Sinai

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2024
• Primary Completion (Actual): October 31, 2024
• Study Completion (Actual): October 31, 2024

Study Registration Dates

• First Submitted: March 6, 2024
• First Submitted That Met QC Criteria: March 12, 2024
• First Posted (Actual): March 15, 2024

Study Record Updates

• Last Update Posted (Actual): August 5, 2025
• Last Update Submitted That Met QC Criteria: July 31, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: STUDY-23-00816

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: overall results will be shared, not individual results

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No