Blue Light (470 nm)
638 THz
Blue visible light at about 470 nm.
How well is this supported?
Measured directly, or defined by a published standard.
This value is measured, or set by a published standard.
About this number
Blue visible light at about 470 nm. Blue light suppresses melatonin production and affects circadian rhythms, the body's daily cycle. A 2001 study found melatonin suppression strongest between 446 and 477 nm.
What is said about it
What is said, not what was measured
Blue light is often linked with light therapy for seasonal affective disorder (SAD). Standard SAD therapy uses bright white light. Blue-enriched light has been tested in trials.
Facts
- Frequency
- 638 THz
- Wavelength (electromagnetic wave)
- 470 nm
- Kind of light
- Blue (470 nm)
- Kind of statement
- Physical measurement
- Filed under
- Radio & light
Sources
- Definitions of visible light and ultraviolet
Where visible light and ultraviolet begin and end. The authorities do not agree exactly on the limits.
CIE International Lighting Vocabulary, terms 17-21-003 (visible radiation) and 17-21-008 (ultraviolet radiation). ISO 21348. BIPM, definition of the candela at 540 THz (555 nm).
View source: Definitions of visible light and ultraviolet - Which wavelengths suppress melatonin
Cited for the range in which suppression was strongest: 446 to 477 nm.
G. C. Brainard et al., Journal of Neuroscience 21 (2001) 6405.