Human Circadian Sensitivity to Very Short Light Pulses

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01330992

Enrollment

400

Registered

2011-04-07

Start date

2009-12-31

Completion date

2011-08-31

Last updated

2011-08-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Circadian Rhythm Disorders

Keywords

Circadian rhythms, Melatonin, Ocular light exposure, Darkness Exposure, Performance, Alertness

Brief summary

The mammalian eye serves both visual and non-image-forming functions. New information about the non-image-forming anatomy and physiology of the eye has revealed effects of ocular light stimuli on human circadian rhythms, melatonin suppression, heart rate, pupillary reflexes, cognitive performance, alertness and sleep. The results of the proposed work can be used to make predictions about the effects of light, to make recommendations involving exposure to or avoidance of light, and to design environmental lighting, resulting in improved health and alertness and decreased errors and accidents.

Interventions

OTHEROcular light or darkness exposure

Ocular light or darkness exposure

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 30 Years

Healthy volunteers

Yes

Inclusion criteria

* Healthy volunteers

Exclusion criteria

* No medications * No eye disease * No sleep disorders * No psychiatric disorders

Design outcomes

Primary

Measure	Time frame	Description
Circadian Phase (hours)	Before and after intervention (day 1)	Circadian phase (hours) measured before and after intervention

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026