Evaluating Color Perception Under LED Red/Green and Green Dominant Light

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01927536

Enrollment

Registered

2013-08-22

Start date

2013-04-23

Completion date

2019-01-10

Last updated

2019-05-15

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

Conditions

Color Blindness, Acquired

Brief summary

The investigators are testing a Light-emitting Diode (LED) flashlight from First-Light™ USA called the Tomahawk MC Tactical Light to determine the range of colors people are able to see with these flashlights at night. The flashlight has been designed to reduce visibility of the user and uses a combination of green and red LED lamps to achieve this. In this study investigators wish to determine how well a subject can differentiate colors at night in a quantifiable manner. Investigators will use the Farnsworth Munsell 100 hue test which requires the user to put shades of red, green, blue and yellow into progressive color order which is scored according to the manufactures specifications.

Interventions

DEVICEWhite LED Flashlight

white light setting

DEVICERed/Green Green Dominant LED Flashlight

Green LED light dominant setting

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to 66 Years

Healthy volunteers

Yes

Inclusion criteria

* normal vision * 18-65 years

Exclusion criteria

* blindness * colorblind * pregnant women * prisoners * decisionally challenged

Design outcomes

Primary

Measure	Time frame	Description
Change in Normal Color vision	1 hr	The Farnsworth Munsell 100 Hue Test is used to determine normal color vision and vision using the red green Tomahawk LED flashlight.

Countries

United States

Outcome results

None listed

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