Time for less light, a lot more vision

At a time when “poor” air quality is greeted with joy as it means an improvement from “severe” and “hazardous” levels, comes the news that we humans are at the forefront of another manmade blight: light pollution. Indeed, the fact that we cannot see stars in the night skies anymore from urban areas has as much to do with noxious particles and gases as our predilection for excessive bright lights. Dark streets are certainly not conducive to urban safety, but do we need, say, the kind of unnecessary multiple lighting sources that Kolkata has been bestowed with in recent years? It may be an inevitable reaction to the dark years of loadshedding under the Left Front, but scientists have been pointing out that relentless bright lights affect the natural rhythms of trees, nocturnal pollinating insects and migratory birds, not to mention the sleep patterns of humans.

So the fact that India and China are getting “brighter” by the day (as per satellite photos) at a time when focused lighting and LEDs should reduce glare is not exactly great news. Contrary to popular perception, brighter lights do not mean better vision as the human eye is more sensitive to contrast than luminance. In other words, less light often results in clearer vision. Authorities everywhere need to understand this and the night sky deserves to be seen everywhere again.