The Science

Why light matters.

Most people think of light in terms of brightness. Scientists think differently.

Light is a spectrum.

The colours we see are only a small part of it. At long wavelengths, red becomes deep red, then near‑infrared. Deep red begins to fade from view. Near‑infrared is entirely invisible.

380 nm 700 nm · sight ends 850 nm · near‑infrared

What happened to indoor light.

380 nm 700 nm · sight ends 670 / 850 nm · deep red & near‑infrared

The full spectrum, visible and invisible — the light we evolved with.

The question

Does restoring the missing spectrum influence human health indoors in meaningful ways?

That question has now been answered by independent university research. 1,2

Independent university study
Human performance 2

A measurable effect on how people perform in real working environments.

Study details ›
Independent university study
Human physiology 1

A measurable physiological response to restored near‑infrared light.

Study details ›
In the press
“The shock revelation that light bulbs are wrecking your metabolism”

New Scientist, August 2026 — on how energy‑efficient lighting removed near‑infrared from indoor life, what that means for mitochondria and metabolism, and the research at UCL.

Read the article ↗
References
  1. Powner M.B. & Jeffery G. (2024). Light stimulation of mitochondria reduces blood glucose levels. Journal of Biophotonics 17(5): e202300521. doi:10.1002/jbio.202300521
  2. Barrett E.M. & Jeffery G. (2026). LED lighting (350–650 nm) undermines human visual performance unless supplemented by wider spectra (400–1500 nm+) like daylight. Scientific Reports. nature.com/articles/s41598-026-35389-6

Full study summaries on the research page.

Restore the missing light.

See how it’s applied