Matthew Walker’s book Why We Sleep is a very good read. He writes beautifully and with well-argued clarity.
Prof Walker gives very compelling evidence that sleep is not an optional human behaviour – that if we want to live well and live long, then ensuring a good night’s sleep (every night and without drugs) will make that more possible.
Why I recommend making a Cossack rather than an Eliza bucket hat.
If you are thinking of buying a light device, make sure that it is made with individual LEDs, not a LED strip.
A device with individual LEDs is more likely to last, it will have better heat management, and it is more likely to be value for money.
As an example, a few weeks ago I made a LED strip device for my back. It uses standard gel-covered LED strip – the sewing is a bit weird but it was functional and felt pretty nice on my back after a day in the garden.
When I first made it, all three LED strips worked very happily. But as of yesterday, one of the LED strips decided to stop working part-way along its length. LED strips do that – they just stop lighting up.
There’s not much I can do about the bung LED strip. I’ll continue to use my home-made device on my back for the moment, but if more of the LED strips decide to conk out, I’ll pull it apart and make another.
The lesson is clear, though.
If you are thinking of buying a commercial light device, avoid those made with LED strips.
I’ve had a query about 12V near-infrared LED strip, especially 850nm LED strip.
You can see 850nm, but only just! 850nm is at the very edge of the eye’s ability to see. If you turn on the 850nm LED strip in a dark room, you will see a nice pale red glow. It’s red, but to our eyes it seems pretty dim. That’s good, that means it is working.