04 — Journal

Notes on light, rooms and hours.

Written after nine, about the light that is left.

6 entriesUpdated 2026

Fig. 01
01 · 4 min read
Why your room goes back to midday at 9pm
The sun sets, and then you switch the lights on and undo it. Here is what actually happens to the light in your room after dark.
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Fig. 02
02 · 5 min read
What 480 nanometres actually means
Every pair of blue-light glasses quotes a number. Here is what ours means, with the measured curve printed rather than described.
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Fig. 03
03 · 5 min read
Clear lenses, amber lenses, and what the difference costs you
Two lenses can both be sold as blue-light glasses and do almost nothing alike. The difference is visible from across a room.
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Fig. 04
04 · 4 min read
The hours that decide your evening
When to put them on, what not to change, and when to take them off. The whole routine is three decisions long.
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Fig. 05
05 · 5 min read
Why cheap blue-light glasses feel like nothing
If you have already tried a $15 pair and felt no difference, you were probably right. Here is what was missing.
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Fig. 06
06 · 4 min read
A frame made for a room with one lamp in it
One frame, one lens, one box. What went into the object you actually put on your face after dark.
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