Those same outdoor lights are also affecting our health. Streetlights are part of the problem, as are sources such as illuminated billboards and stadium lights. 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. But the rise of LEDs is also illuminating new problems for our night sky, as well as our health. Traditional orange-tinged high-pressure sodium bulbs are being swapped for more energy-efficient, whiter and brighter LED (light-emitting diode) lights. In recent years, cities, towns and small communities across the world have taken part in a radical revolution - of our lightbulbs. Please enable JavaScript for the best experience. Warning: This graphic requires JavaScript.
