How can light pollution be prevented?

Answer 1

There are valid arguments on each side of the "light pollution" debate. Astronomers dislike stray light that makes it difficult to see the stars, while police and city planners - and residents - know that street lighting and security lighting deter criminals, who would rather practice their vile trade in the dark, and makes it safer for drivers. So the question is, is there a way to light the cities, but not the skies?

There is no escape. Light bounces, reflects, scatters. You can't point lights at the ground and not have reflections back into the sky. Which is not to say that engineers can't try to minimize the effects.

Many street lights and city lights point UP. This may be pretty, but does nothing to enhance security while magnifying the problems of light pollution. Street lights and security lights should be shaded to not point to the sky.

Really, though, it boils down to a decision about who gets inconvenienced; a few astronomers, or millions of citizens?

Go out of the city so you can see the stars the only way to not have light pollution is to turn them all off

Answer 2

In my opinion it can not stop completely but can be reduced by aiming it properly i.e it should not be emitted above the source's horizontal plane

Answer 3

Only use light when it is absolutely needed and use shielded street lights that re-direct light downwards instead of up into the sky.