The hour before sleep belongs to your eyes

You've already done the work. You've eaten, you've stopped checking email, you're on the sofa. And then, without noticing, you've opened your phone three times in ten minutes.

The problem isn't the phone. The problem is the wavelength coming out of it.

Blue light the 460–490 nanometre band that makes screens feel crisp and daylight bulbs feel bright which suppresses melatonin production for about two hours after exposure. Your body reads it as noon. At 10 pm, this is the exact wrong information.

There are two paths out of this. Remove the light. Or filter it.

Removing it means changing the bulbs in the room where you wind down. A warm-spectrum bulb below 2700K cuts the blue signal entirely which the ambient reading changes from "office" to "room." Filtering it means tinted lenses that absorb the same wavelengths while letting the rest of the light through. Orange lenses catch some of it. Red lenses catch nearly all of it.

Neither is elegant until it becomes a habit. The lamp clicks on around 9. The glasses go on when the phone comes out. You stop deciding every night.

The softer the last hour, the earlier sleep arrives.