The story of the dark sky is more than one of stargazing and astronomy. It has become one of human and animal /insect /plant well-being as light pollution intensifies and spreads itself through its terrestrial impacts. This BBC science item is the latest to underline the impact of light on the natural world.
In 2018, The Royal Society of New Zealand, Te Apārangi published a study called: “Evidence Summary on how our increasing exposure to artificial blue light is putting us at risk in New Zealand“.
This paper summaries the latest evidence on this topic and explores what we can do to protect ourselves and the environment from the effects of exposure to artificial blue light outside daylight hours.
Skyglow is the brightening of the night sky over inhabited areas, which reduces the contrast of stars or other celestial objects against the dark sky background. Some stars will blend into the background and become indistinguishable.
Clutter is the bright, confusing and excessive groupings of light sources, such as many lit advertisements signs in one place.
At night, too many lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents.
Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertisements surrounds the roadways. Depending on the motives of the person or organization that installed the lights, their placement and design can even be intended to distract drivers, and can contribute to accidents.
Glare is excessive brightness that causes visual discomfort, just like when a car blinds you with its headlights at night.
Glare from unshielded lighting is a public-health hazard—especially the older you become. Glare light scattering in the eye causes loss of contrast, sometimes blinds you temporarily and leads to unsafe driving conditions, for instance.
Glare can be disabling or simply uncomfortable. It is subjective, and sensitivity to glare can vary widely. Older people are usually more sensitive to glare due to the aging characteristics of the eye. Disability glare is the reduction in visibility caused by intense light sources in the field of view, while discomfort glare is the sensation of annoyance or even pain induced by overly bright sources (Rea 2000). Reducing glare is an effective way to improve the lighting.