In recent years, cities, towns and small communities across the world have taken part in a radical revolution — of our lightbulbs. Traditional orange-tinged high-pressure sodium bulbs are being swapped for more energy-efficient, whiter and brighter LED (light-emitting diode) lights. But the rise of LEDs is also illuminating new problems for our night sky, as well as our health.

Over the past decade, scientists found, the night sky has become nearly 10 percent brighter each year because of artificial lights, mainly LEDs emitting too much glare. Streetlights are part of the problem, as are sources such as illuminated billboards and stadium lights.

Lights near stadiums can often be the brightest light source of a city and can be minimized by using timers or dimmers.

Those same outdoor lights are also affecting our health. Common types of LED lights contain higher proportions of bluer wavelengths, which can affect people’s nighttime patterns. They disrupt our circadian rhythms, lower the performance of our immune systems and increase the occurrence of certain diseases, including cancer.

“People need to […]