The science behind BioCentric Lighting™ lies in the understanding of human anatomy and our responsiveness to light. Increasing amounts of research reiterate the importance of daylight for our health, wellbeing, and sleep. Light research is continuously integrated into our lighting systems, ensuring we deliver the best scientifically-based lighting environments for all needs.
Chronobiology is gaining importance in the understanding of human physiology. The innate rhythmicity of biological functions, where most fluctuate according to a circadian rhythm, thus prepare the body for daily recurring events such as eating and sleeping. The pancreatic clock regulates insulin secretion and its response to glucose; the hepatic clock regulates glucose clearance, the skeletal muscle clock regulates metabolism and glucose uptake, and so on³⁶. The suprachiasmatic nucleus in the hypothalamus is the synchronizer for all of the clocks in the body. It adjusts the production of hormones such as melatonin and cortisol. The timing of these processes is collectively called our circadian rhythm. Recent evidence points to a genetic variability of clock genes associated with individual differences in sleep and circadian physiology and non-visual response to light³⁷.
Light is the most important time cue.
Light is the most important time cue for the circadian rhythm¹⁵. Light stimulates via melanopsin-containing ganglion cells through the retinohypothalamic pathway the suprachiasmatic nucleus (SCN)¹⁶. The SCN in the hypothalamus is the master clock in the human brain and controls the circadian rhythm¹⁷.
Most people have a biological rhythm close to 24 hours.
As in other mammals, in humans, the biological clock shows only a small variation between individuals. Most people have a circadian rhythm that is slightly longer than 24 hours¹² which means that it needs to be corrected daily in relation to the solar day¹³. Without correction, the circadian rhythm is shifted slightly every day and gradually falls out of phase compared to the 24-hour solar day¹³.
It all starts in the eye. Eye formation begins 22 days into embryonic development, and the eye constantly develops up to the age of 6-8 years. In the back of the eye we have the retina which consists of several layers. Outermost are the photoreceptors. Up until 2000 it was believed to only exist two types of photoreceptors, rods and cones. Recently a third photoreceptor with its own wavelength, separated from that of rods and cones, was discovered. Furthermore, this receptor was found in the ganglion cell layer and not in the photoreceptor layer of the retina. It contains melanopsin, a photopigment different from that of rods and cones with a spectra around 480 nm. The ganglion cells in the retina form the optic nerve that transport light
information to the brain from the eye. Most of the nerve fibres projects to the visual cortex in the back of the brain. However approximately 5% of the nerve fibres, those from the melanopsin containing ganglion cells, project directly on to hypothalamus and the suprachiasmatic
nucleus where light information is used to synchronize the circadian rhythm with our surroundings.
"Several parts of the brain are activated by light."
Words from an Ophthalmologist
Madeleine Selvander, member of our Scientific Advisory Board, gives her expert opinion on light and its relation to our well-being.
What are the direct effects of light on our eyes?
Light is transformed to a visual signal that is interpreted in the visual cortex in the back of the brain. Besides the visual response, several other parts of the brain are also activated by light. Multiple alerting and sleep regulating structures in the hypothalamus receive direct input from the retinal ganglion cells when light hits the eye. That is why light at night can cause insomnia, but also have a direct alerting effect. Through the preoptic nucleus in the brain, activity is also seen in the amygdala when the eye is exposed to light. The amygdala is considered part of the limbic system of the brain which regulates our emotions. This explains the direct mood enhancing effect of light, especially light with lower wavelength. Who hasn’t felt happy on a bright, sunny day?
Can light have a negative effect?
Light is the most important zeitgeber for the circadian rhythm. Light at night, especially light with shorter wavelength, can suppress the sleep hormone melatonin and thereby cause insomnia. One way of protecting yourself is to switch to night mode on electronic visual equipment and to avoid bright light before bedtime. Another good strategy is to expose yourself for light during daytime. Appropriate light during daytime has found to be protective towards detrimental light in the evening.
What made you interested in BioCentric Lighting™ and how has it affected your practice?
I find the fact that light not only has a visual, but a direct effect on alertness and well-being, very interesting. Furthermore the discovery that appropriate light at the right time, which is possible with BioCentric Lighting™, can improve sleep and thereby improve long term health. We know that most people get insufficient amounts of light to stimulate the circadian rhythm optimally. Patients with retinal diseases such as glaucoma are at higher risk of developing sleep disorders. Proper timing and sufficient light is therefore especially important for this group of patients, to synchronize their circadian rhythm.
Modern LED technology has introduced the possibility to adapt color saturation and brightness. Terms such as ”tunable white” and ”dynamic white” are often used within the lighting industry. The subsequent effect lighting has on health has led to the birth of a new term; Human Centric Lighting (HCL). However, to succeed in creating healthy lighting environments, both the LED technology and basic anatomy need to be considered. At BrainLit we use luminaries, sensors and control systems that adapt to real human needs instead of present standards. This is what we call BioCentric Lighting™. After years of extensive scientific research, we have produced innovative lighting environments that cater to individual needs.
10% of the energy used in generating light ends up towards useful lighting
Traditional lighting sources fail to regulate the circadian rhythm due to insufficient temperature, brightness or dynamic changes. It is estimated that 15-20% of global electricity consumption is used with the purpose to generate lighting, from which less than 10% of the energy ends up in useful light. This is caused by bad conversions or useless lighting, ”light pollution”. In addition, poor lighting environments with flickering and low intensity luminaires lead to high maintenance costs and negative health effects on humans and animals.
Our LED technology is advanced in its endless possibilities for individual preferences and needs. Our luminaires follow the natural daylight curve closely and mimics it both in intensity and color. Our lighting can be both static and dynamic depending on use and is always customizable. Personalized lighting following the natural daylight pattern, with scientific recommendation, is unique in the industry. Try BioCentric Lighting™ today and discover the difference.