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21 June 2018
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Light of day

18 April 2017 | Helen Loomes

Helen Loomes of Trilux says that FMs should consider different types of light intensity and colour temperature when specifying lighting systems to improve workplace cognition levels (see Perspectives).

Loomes explains that our biological circadian rhythms respond to light that follows a natural day / night rhythm. 

“Light enters the eye via the lens and reaches the retina at the back of our eye-ball,” says Loomes. “When it reaches the retina, it passes a layer of ganglion cells and bipolar cells. Then it reaches the layer where cones and rod are: cones interpret colours, while rods process low-light level vision.

"In 2001 it was discovered that there is a third receptor that responds to light – ‘intrinsically photosensitive retinal ganglion cells’, located just in front of the rods and cones. These respond only to blue wavelengths of light, a function that regulates our biological clock. When blue light is present, a signal passes through the nervous system and via the suprachiasmatic nucleus (effectively the circadian clock) to a part of the brain (pineal gland) that produces certain hormones. This system prepares us for sleep at the end of the day, when blue light is at a lower intensity. But it also keeps us alert during the day when there is a high level of blue light. It’s something to think about when considering that next fit-out project."

Helen Loomes is business development director at Trilux Lighting

eyeball image diagram