I do not use LED lamps in my home. White light is not a single wavelength; it is produced by a combination of different wavelengths across the visible spectrum, including red, green and blue.. Exposure to blue light may have long-term effects on the brain and circadian system. Bright light, especially blue-enriched light, can stimulate the brain’s circadian system and influence the hypothalamic–pituitary–adrenal (HPA) axis, which regulates cortisol. Intrinsically photosensitive retinal ganglion cells (ipRGCs) detect this light and send signals to the suprachiasmatic nucleus (SCN), the body’s biological clock. Some research has also suggested that blue light may influence behaviour.

Research by Professor Glen Jeffery at University College London suggests that mitochondria, the powerhouses of our cells, may benefit from red and near-infrared wavelengths. His research indicates that exposure to these wavelengths can influence mitochondrial respiration and cellular energy production. This suggests that the lack of a natural light spectrum may be more than just a matter of eye strain; it may also have broader biological effects. Studies have found that exposure to specific red and near-infrared wavelengths can influence mitochondrial activity, glucose metabolism and oxygen consumption.  Choose your home lighting wisely. The right light matters.

Originally written on 1 August 2026

Edited on 17 August 2026