TRY THESE SIMPLE TRICKS TO PROTECT YOURSELF...

BRIGHT light at night — especially blue light from the LED bulbs in computer screens and, increasingly, in ceiling lights and street lights — undermines our ability to sleep.

Adjusting the light settings on your phone or tablet — or installing an app that filters out blue light after sunset — can help.

Even so, most sleep researchers advocate ditching screens altogether in the half-hour before bed — and, ideally, for several hours beforehand — because even relatively dim light sources held close to the eyes can inhibit the sleep hormone melatonin.

Try to get outside more during the day, particularly in the morning. We measure illuminance in lux, which refers to the amount of light striking a surface.

The full moon on a clear night is 0.1 to 0.3 lux, or up to 1 lux in the tropics — about the same as candlelight. The illuminance in a typical office is between 100 and 300 lux during the day, whereas even on a gloomy, overcast winter’s day, it will be at least ten times brighter if you’re outside.

On a clear summer’s day, when the sun is higher in the sky, it can reach 100,000 lux.

In the West, we spend our daytime in the equivalent of twilight, then keep the lights switched on well after sunset. Some of us even sleep with a nightlight on, while citydwellers often have light pollution from street lights with which to contend.

A recent German study found exposure to bright light in the morning boosted people’s reaction times and speeds and maintained them at a higher level all day.

So take a morning walk, eat breakfast next to a large, east-facing window bathed in bright morning light, or quit the gym and instead exercise outside. If it’s cold or wet, remember there is no such thing as bad weather — just the wrong clothes.