What is Light pollution?
'''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. Light pollution costs Americans [[1,000,000,000|billion]]s of dollars every year. == Types of light pollution == 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 cannot 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 == === 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, so they cannot 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 because a camera flash 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