When should you put on your evening glasses?
Approximately two hours before you want to go to sleep. This is when your body starts producing melatonin, and precisely then, the light you receive has the greatest impact.
Putting them on later still helps, but less so. Ten minutes before sleep is too late, as the inhibition will have already occurred.
Why two hours?
Because the run-up to sleep is a process, not a switch. Your body temperature drops, melatonin production begins, and your alertness decreases. Light during this phase interrupts that process.
How this inhibition works is explained in blue light and sleep.
How do you adjust this to your bedtime?
Count back two hours from the moment you normally fall asleep, not from the moment you go to bed. For many people, this makes a difference of half an hour.
| You fall asleep around | Glasses on from |
|---|---|
| 10:30 PM | 8:30 PM |
| 11:00 PM | 9:00 PM |
| 12:00 AM | 10:00 PM |
| 01:00 AM | 11:00 PM |
If you work shifts, this shifts with your sleep time and not with the clock.
Should you wear them until you're in bed?
Until the lights go out. If you take them off while you're still on your phone for half an hour, you'll negate much of the effect.
The simplest moment to take them off is when you turn off the lights and aren't looking at anything anymore.
What if you don't notice anything?
Give it two weeks and don't change anything else during that period. If you still don't notice anything, light probably plays a smaller role for you than the content of what you're looking at.
This is not a failure of the glasses but useful information. Why this sensitivity differs per person is explained in why not everyone reacts the same. Our SLEEP has a thirty-day trial period, precisely so you can do that test.
This article is intended as an explanation, not as medical advice. For persistent sleep problems, a general practitioner is the appropriate contact.
