Light Pollution

Chicago at night aerial photograph Credit Jim Richardson/International Dark-Sky Association

Chicago at night aerial photograph by Jim Richardson

Light Pollution

Light Pollution is defined as: inappropriate or excessive use of artificial light. It’s split into four categories.
  • Glare - Excessive brightness that causes visual discomfort
  • Skyglow - Brightening of the night that reduces the visibility of the stars
  • Light Trespass - Light falling where it’s not intended
  • Clutter - Bright, confusing, and excessive groupings of light

In most cases outdoor lighting is not properly used. They are often unshielded and untargeted allowing light to spill into the sky and trespass over areas where it’s not needed. And the excessive use of lights at night culminate to block our view of the stars.

Life on Earth adheres to the natural cycle of day and night. However, artificial lighting disrupts that rhythm, illuminating the dark.


Plants and animals depend on this cycle to keep up their natural behaviors such as nourishment, reproduction, sleep, and protection from predators. For example, frogs and toads use their croaking at nighttime for breeding. Artificial lights are suggested to be a potential cause for their population decline. Either by lights attracting insects (their prey) away from them or delay their breeding ritual. Baby sea turtles are also affected. They use the moonlight to guide them to the sea/ocean, however are misguided by bright city lights.



Wildlife aren’t the only ones affected, us humans are harmed as well. We we are bound to our circadian rhythm (our biological clock, sleep-wake pattern) which is governed by the day and night cycle. Artificial lighting tricks our bodies to believe it's still daytime, this is true especially from blue light sources such as LED's or electronic devices with screens. Blue light can simulate daylight because of the strength of the light (wavelength/frequency). Melatonin regulates our circadian rhythm, boosts the immune system, along with other necessary functions. However, exposure to blue light during nighttime can suppress this essential hormone, which can affect our quality of sleep and other bodily functions.

Light pollution is often overlooked as a serious issue. Millions of people never truly experience the night sky and see the Milky Way with their own eyes because of skyglow. You can take a look at NASA’s Blue Marble Navigator to understand the severity of our use of lights.


Taken during the 2003 Northeast blackout, affected 55 million people.  

Photo by Todd Carlson

On the bright side, light pollution can easily be reversed. You can help by having your lights be fully shielded, have motion detectors for when you need light, and of course spreading the word helps.

Buda is a community that appreciates nature with a small town feel. We’re different than a big city with its many lights and busy streets. Here we feel more connected with our environment and as such, what better way to breathe easy than experience the stars.

Information gathered from these resources:

International Dark Sky Association
Harvard Medical School