Adopt these simple practices to adjust your light exposure and improve your focus, alertness, and productivity.
As a diurnal species, light regulates our circadian rhythm and hormones, impacting our sleep, mood, wakefulness, metabolism, learning, and memory. In developed countries, our lifestyle has moved primarily indoors, reducing sunlight and increasing artificial light exposure. Insufficient light during the day and excessive light at night are the primary causes of insomnia and are thought to be one of the main drivers of the rise in psychiatric disorders in modern society. Nighttime light is associated with worse mental health outcomes and conditions including major depressive disorder, anxiety, bipolar disorder, and PTSD.
The sun is the most powerful source of light in our environments, providing more light than any standard artificial light source. Our body has evolved in response to sunlight; melanopsin cells in our eyes detect the unique combination of blue and yellow light present near sunrise and sunset, promoting wakefulness in the morning and sleep in the evening. Sunlight also has direct effects on our endocrine system, boosting mood and reducing stress. Note that sun exposure through windows or sunglasses blunts its effects.
Having regular exposure to light that aligns with our circadian rhythm has tremendous benefits on wellness and productivity. Here are the evidence-based practices we've found to be most beneficial and implement on a daily basis.
Maximize light after waking
Bright light soon after waking signals to our body that it is time to start the day and activates physiological processes guiding our circadian rhythm and cognition. Light exposure during this time promotes an early cortisol peak and dopamine release, which helps awaken and focus the mind.
Sunlight is the best source to use, as it is significantly brighter than nearly all artificial lights.
Maximize light during the day
Bright light during the day increases energy, productivity, and mood. It blocks the effects of the neuromodulator adenosine, which accumulates during the day and is responsible for the feeling of sleepiness. Sufficient daytime light maintains dopamine, cortisol, and adrenaline levels, boosting alertness and focus.
Sunlight has the added benefit of balancing hormones and neurotransmitters like testosterone, cortisol, and serotonin, enhancing mood, energy, and neurological function.
Get afternoon/evening sunlight
The unique mixture of blue and yellow light set low in the sky has a unique effect on our melanopsin cells that reduces the harmful effects of nighttime light exposure. Late afternoon and evening sun viewing inoculates our eyes from bright lights seen later, moderating their effect.
Being outdoors for 20 minutes 1-3 hours before sunset, depending on time of year, can reduce the negative impact that our artificial lighting environments have on our physiology.
Minimize light at night
In addition to blocking adenosine, light also blocks melatonin, which is the hormone that signals to our body that it's time to sleep. Bright light exposure late at night prevents adenosine and melatonin from satisfying their roles in preparing the body to release other hormones and regulate sleep processes. While blue light is the most potent inhibitor of these functions, red light does not seem to have as detrimental of an effect.
Regularly dimming lights 2-3 hours prior to sleep and installing warm (yellow) lights or red lights will help promote initial sleep processes and ensure higher quality sleep.
Minimize light during sleep
Viewing light during times we would normally be sleeping confuses our circadian processes and disrupts endocrine and neurological function. This negatively impacts sleep onset, duration, and quality. It is also associated with increased instance and severity of mental health conditions, including depression, anxiety, PTSD, bipolar disorder, and psychosis.
Avoid blue or white light, especially during the hours of 10pm-4am. If light is required, use a red light source whenever possible.
Have these practices benefitted your sleep quality and duration? Leave a comment and let us know!
