Sunlight, blue light, red light, sleep tight!

Virginie Gabel is a neuroscientist and a specialist in light and sleep

cycles. Why do we sleep less when we're older and why do screens ruin our

sleep? Why is our circadian rhythm important to our health, and how long

should a "disco nap" be?

These are all important questions we tackled with her over our coffee and

croissants.