The Bad Rap of Blue Light

By: Rachel Bannon-Godfrey, Rachel Fitzgerald and Katherine Stekr

RECENT HEADLINES BLAME BLUE LIGHT FOR THE CURRENT SLEEP DEPRIVATION CRISIS. But what does that really mean?  Why is blue light so bad?  More importantly, how does it affect you and the built environment?

We are living in a glowing age of information – literally. We are constantly bathed in light from a barrage of sources – phones, watches, computer screens, TVs, fitness trackers – you name it, and most anything with a screen or digital output has a component light in the blue spectrum. As technology brings smarter devices into our lives, our awareness of the potential detrimental effects on the human body has grown. Artificial blue light has been shown to disrupt our natural sleep patterns. According to recent studies, sleep disorders contribute to multiple health ailments – from Type 2 Diabetes, obesity, cancer, heart disease, and clinical depression. The dangers are real, but there’s also a lot of misinformation that paints blue light as the enemy. The key is all in the timing.

When Blue Light is the Good Guy

We actually need blue light. It is an important part of how our biological time-clock functions; it controls our Circadian Rhythm, which is in charge of our sleep/wake cycle. Blue light entering the eye in the morning and throughout the day suppresses our body’s production of Melatonin and increases the production of Serotonin and Dopamine. This allows us to be alert during the day. Blue light is in league with the blue sky and the high angle of the sun, which is mimicked by the overhead lighting in most offices. We need sources of blue light during the day, as many of us spend most of our waking hours in the built environment where access to natural daylight is often limited.

When Blue Light Is the Bad Guy

 As the sun sets, the angle of light into our eye decreases and the ‘color’ of the light shifts from blue to a warmer amber color. This shift increases the production of Melatonin in the body. This is the body’s natural sleep aide, helping you fall asleep and stay asleep. Blue light at night, even for a millisecond, resets the body’s internal clock and disrupts all these processes. Prolonged exposure to blue light right before bedtime prohibits your body from performing normal brain and body functions that keep us healthy. Studies have shown significant negative health impacts with exposure to blue light after 8 p.m. It has been linked to higher incidences of cancer in shift workers and greater instances of confusion and disorientation in those affected with Alzheimer’s.


So how can those of us who have an impact on the built environment support a healthy balance of light?


Circadian Lighting

The term circadian lighting essentially refers to a system with the potential to produce lighting sequences that stimulate cortisol production (blue light) during peak daylight and suppress melatonin production (elimination of blue light) at night. Put simply, circadian lighting tries to imitate the light patterns we would have experienced before the built environment and technology came along. Caveman lighting, if you will.

Addressing Circadian Lighting in the Built Environment

Achieving the perfect ‘caveman’ circadian lighting is no easy feat. The typical person today spends 90 percent of our time indoors, under a growing amount of LED lighting, which has a component of blue light. Thought is now being put into how a shift in the color temperature and output of LED lights could address circadian disruption currently happening in most buildings. At RNL, as designers and architects of the built environment, we see more opportunity to implement LED lighting systems with variable outputs which mimic the color output of the sun, providing the good peak blue light output at mid-day, eliminating the blue light component at night with warmer white outputs.

It Takes a Village

The problem with (and solution to) circadian-related health impacts is not the sole responsibility of the architectural lighting community. RNL strongly believes the key to solving this problem lies in cross-disciplinary partnerships. We are actively collaborating with not only lighting designers, manufacturers and architects, but also public health and medical professionals, urban planners and municipalities. Society has become alarmingly dependent on glowing screens. Ultimately, collaboration needs to extend to the electronics and wearables industry. If we can create lighting systems tuned to follow our circadian rhythm, then why not every light we find ourselves exposed to? If the designers and engineers of our spaces, places and devices work together, we can find solutions that keep us digitally connected, well illuminated, and biologically in sync. We can get that healthy caveman lighting back, but it’s going to take a significant re-tooling of technology and re-training of personal habits to get us there.