**Light pollution** is a type of pollution. It is defined as "any adverse (or bad) effect as a result of man-made lights." Usually, this means too much light. Several species, including plants and humans, are badly affected by light pollution. Most people have never heard of light pollution, and those who have usually don’t care, or do anything about it. Light pollution costs Americans billions of dollars every year.

Types of light pollution
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There are five kinds of light pollution:

* Light trespass
* Over-illumination
* Clutter
* Glare
* Sky glow

Sky glow usually has more of an effect on the environment than light trespass and glare, but all of them are a major problem to people today.

Sky glow is the kind of light pollution that prevents people from seeing stars and other deep-space objects. This causes birds to not be able to migrate to the right place because they can not follow the moon and stars. Sky glow also prevents astronomers from seeing dim objects.

Light trespass is when light being used by a person goes into the property of another. Although light trespass is not an environmental issue, it is still light pollution.

The third kind of light pollution, glare, has different kinds. The first, disability glare, is the loss of visibility because of too many lights. Discomfort glare is when the lights cause pain.

Effects
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### Effects on animals

Light pollution stops migrating birds from having any way of seeing the moon and stars that they need to use to navigate the direction of their migration, therefore not being able to migrate to the correct place. Also, sea turtles do not come to shore and nest as often, because they are afraid of the lights. It also affects animals eyes as a flash of camera weakens the eyesight of animals.

### Effects on humans

Glare causes sleep problems in humans. For example, too much light in an apartment shining in from a nearby billboard will disturb their sleep. Science, too, is being affected by light pollution. Astronomers have no way of observing or making discoveries with too much light to block the night sky.
Light pollution also causes headaches when light directly falls into our eyes and affects the sensory nerves.

The solution
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### Group solution

There are now several groups that are trying to prevent light pollution. Light pollution first made news in 1964, when an observatory was specially placed just to avoid light pollution. However, it wasn’t brought to the attention of most people until June 6, 2002, when the Czech Republic passed the world’s first light pollution law. Since then, light pollution is slowly being recognized by the general public as a major problem.

Also government should pay attention for advertisements, which produce the greatest amount of light.

### Individual solution

You can lower the amount of light pollution by having lights off when they are not needed. You can also shield yourself from this pollution by putting curtains on a window facing the street or any other disturbing light source.
We can also use automatic lights. If we come in range of it, it will turn on, otherwise it stays off. This way we can save electricity and reduce light pollution.