Dark Skies and Autism
The following post was written by Isaac Koerner, a DarkSky advocate from Torrance. Isaac recently shared this personal letter about the impact that harsh LED lighting can have on people with autism and sensory sensitivities. As brighter LED lighting becomes increasingly common in public spaces, his experience raises important questions about accessibility, public health, and how lighting can be designed more thoughtfully while still supporting energy efficiency. The letter can also serve as one that may be shared with city officials to help raise awareness and encourage more responsible dark sky lighting practices.
To whom it may concern,
As you know, the world is rapidly moving towards LED lighting. This includes almost every type of light that we interact with, including streetlights, automobile headlights, emergency and maintenance vehicle flashing lights, and almost every other type of light.
A large group of Americans with autism spectrum disorder are extremely bothered by the intensity of undiffused LED lighting, combined with its cool white color and small source area. I understand the importance of sustainability, and I want to share ways that LEDs could be more responsibly implemented to meet the needs of both the environment and sensory sensitive people like myself. I discuss specific suggestions later under the “what can be done” section near the bottom of this letter.
This issue has deeply affected me personally:
I have a psychiatric diagnosis for high functioning autism (formerly known as Aspergers syndrome). Autism is a neurological disorder which is characterized by sensory processing problems (source 1*: Sensory differences - a guide for all audiences). In other words, I am easily overwhelmed by high levels of sensory input. This includes light, noise, touch, and smell. Noisy environments or bright flashing lights are very bothersome to me. If I am subjected to them on a daily basis (like LED lights in the place where I live), I can even start to develop chronic anxiety. A year ago, I had something akin to a nervous breakdown due to chronic exposure to a combination of harsh lighting and small aircraft noise where I lived. This was so severe that I quit my job and left my relationship to move back home. I am back to my life now, but as long as undiffused, ultra-bright LEDs are prevalent in our public spaces, I have to be careful to prevent relapse. This means I live with serious restrictions such as inability to drive or walk outside at night for a prolonged period of time. This is obviously a serious logistical challenge.
This is a neurological response that I cannot control. I've spoken with researchers in autism who say there is currently no treatment or cure for autism-induced sensory sensitivity. As you can imagine recent transition to LEDs and the resultant excess and unnecessary amount of bright light in public places is very frustrating for me.
I am not the only one who has been so greatly affected by this issue:
You will find several threads online where people complain about LED lights causing them severe discomfort. See softlights.org for some stories of people who are bothered by harsh and bright lighting, specifically automobile headlights and emergency vehicle lights. Based on my experience interacting with these online forums and websites, several of the people who share their stories around the internet have autism.
You can also find thousands of people on reddit with complaints similar to those found on softlights.org.
This is an issue of accessibility of public spaces for people with Disabilities:
As was made clear above, harsh lighting, combined with my autism, has been life-changing for me and others. It is extremely restrictive of my activities, similar in principle to someone that is wheelchair-bound or otherwise restricted by a disability. We dedicate significant public funding and enact laws to making public infrastructure accessible to blind and wheelchair-bound people (speakers on crosswalks for blind people, ramps for wheelchairs). I believe that we should also invest in infrastructure adaptations and make laws regulating headlights for the benefit of people like me who are unable to access outdoor spaces at night due to a neurological disorder.
What specifically can be done?
As with any new technology (cell phones, chemicals, etc.), industry is often hasty in commercialization. Consequently, widespread adaptation occurs before we've had time to study the negative effects and implement proper regulation.
I understand and support the important sustainability advantages of LED lighting. With some adjustments, we can meet the needs of people with sensory sensitivities while still using energy-saving LED technology. The below section will describe how I believe we could responsibly implement LEDs.
Before going into the details, I want to explain a little background of exactly what aspect of harsh lighting is most bothersome for people with sensory processing disorders.
The issue is not as much with the absolute brightness level, but the surface brightness density of the brightest object in my view (nits, not candela). The brightest object my view is, of course, the light source. For example, a room can be very bright but if the light source is hidden, I’m not bothered. Conversely, if a room is relatively dim, but the only illumination comes from a phone light with a tiny led element, and that tiny light source is in my vision, I will be very bothered. Since LEDs, by nature, have a much smaller size than other light sources, the also naturally have a much higher surface brightness density than other light sources. This is why it is especially important to make sure LED light sources are properly diffused, or even better, not visible.
With that, I will go into my first recommendation:
1. Whenever possible, hide the light source
For indoor spaces, shine the light upwards to the (non-reflective) ceiling, and let the ceiling diffuse the light more evenly into the room
For outdoor spaces, add a (large) diffuser to the light fixtures, so spread the source over a much larger surface, therefore reducing the surface brightness density (nits)
2. Regulate the maximum brightness of exceptionally bright lights
In some cases, such as vehicle headlights and emergency flashing lights, the light is so incredibly bright that adding a diffuser is not enough. Lights like these quite simply need to be made dimmer. There is no way around it.
Just because lights are cheaper to run now (energy efficiency), doesn't mean we should have more and brighter lights in our public space. I understand the need for visibility and safety, but the current level of brightness is excessive. For the case of vehicle headlights, some will argue that the headlight shines down at the road, so it is not an issue. However, we have all experienced frequent cases of LED headlights shining up into our eyes while driving. The road is not perfectly flat and any slight deviation will cause the car to angle up, causing the full headlight intensity to shine into the drivers eyes. The result is an INSANE amount of light that, from my own experience, is attention-grabbing even at a distance of over a mile. At a distance of only a few dozen feet, this intense brightness is not only incredibly bothersome to neurologically sensitive people, it is unsafe (due to blinding oncoming traffic).
People seem to think that brighter is better, but clearly that is not always true.
3. Utilize shields and angle lights away from people's eyes
This suggestion is mostly aimed at streetlights and other public lighting. Lights should be illuminating the surfaces they are meant to illuminate in a targeted fashion. For example, a light meant to illuminate the sidewalk should not be shining into people’s eyes. Due to the superior brightness of LEDs, we should take extra care to properly shield and angle lights away from people's eyes. I know several people who have a bright LED street light that shines into their apartment window all night long.
4. Use a yellow phosphor instead of a white phosphor on LED lighting.
This can apply to any type of lighting, from vehicle headlights to streetlights. Warm white LEDs are generally considered by neuroscience experts to be less neurologically stimulating, and generally more comfortable to look at, than cool white ones.
Sincerely,
Isaac Koerner
*Source 1 url: https://www.autism.org.uk/advice-and-guidance/topics/sensory-differences/sensory-differences/all-audiences
