Impacts
Light pollution's Impact on Nature
Birds
Some birds who migrate at night, use the light from stars, the setting sun, and the moon, for navigation.
Unfortunately, artificial lights interfere with birds' natural instincts. They get drawn towards brightly lit urban places, and they become trapped in areas with little food to survive.
They also often collide with brightly lit structures, or circle them until they drop down from exhaustion.
Finally, if they are injured or stunned by the lights, they are vulnerable to predators.
Turtles
Baby sea turtles, born on beaches, hatch and find their way to the sea because the moon's light reflects onto the seawater.
However, the artificial lights from urban areas confuse the turtles, and they sometimes never reach the seas — which are their homes.
Insects
Bright objects attract many insects at night.
Predators take advantage of this, and the insects become prey.
Plants
Nighttime lighting drives away nocturnal pollinators.
This results in plants in lit areas reduce their ability to produce fruits.
Sediments
Some freshwater sediments are able to photosynthesize under low light levels.
Artificial illumination at night can increase the proportion of microorganisms in them.
Animals
Animals have an internal body clock, which determine their timing of sleep, foraging, mating, and migration.
Artificial light can disrupt that body clock, which results in altering their natural timing of events.
Light pollution's Impact on Humanity
Damage of cells in eyes
Excess light can actually damage certain cells called photoreceptor cells in the retina of the eyes.
This causes bad eyesight.
Disruption of Sleep Cycle
Too much exposure to artificial light at night can confuse the brain into thinking it is daytime when it's nighttime.
This can also cause sleep deprivation, because the body is not ready to sleep when it thinks that it is daytime.