It’s a sad fact that many children will grow up never seeing the Milky Way, our own galaxy, because of the impact of artificial light.

Light pollution is a generic term referring to artificial light which shines where it is neither wanted nor needed. In broad terms, there are three types of light pollution:

• skyglow – the pink or orange glow we see for miles around towns and cities, spreading deep into the countryside, caused by a scattering of artificial light by airborne dust and water droplets
• glare – the uncomfortable brightness of a light source
• light intrusion – light spilling beyond the boundary of the property on which a light is located, sometimes shining through windows and curtains

There is increasing awareness of the impact that light pollution can have on wildlife, by interrupting natural rhythms including migration, reproduction and feeding patterns. Man-made light is known to cause confusion to migrating birds, often with fatal outcomes, and many of us will have heard birds singing late into the night in trees lit by a streetlight.

A survey by CPRE found that light pollution can cause a great deal of distress to humans too, including disrupted sleep, and in some cases has driven people to move house to get away from light pollution. Recent studies suggest that exposure to light at night can disrupt the body's production of melatonin, a brain hormone best known for its daily role in resetting the body's biological clock.