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Find the Odd Disk

(colors2.alessandroroussel.com)
192 points layer8 | 3 comments | 20 Apr 25 19:17 UTC | HN request time: 0.427s | source
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nuancebydefault ◴[20 Apr 25 19:56 UTC] No.43746131[source]▶
What stood out a lot in this exercise is that when looking at, versus near a disc, its luminance (or maybe the color as well) is perceived as changing. Almost the same i have when staring at not too bright stars, they seem to disappear when staring directly on them.

And related, I once had an 'eye migrane'. During that half an hour, the figures of a clock disappeared the moment i looked at them.

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1. Liftyee ◴[21 Apr 25 02:34 UTC] No.43748062[source]▶
I experienced this too. IIRC the brightness-sensitive rod cells are more concentrated in your peripheral vision while your central vision has more colour-sensitive cone cells. This makes the centre of your vision less sensitive to dim objects, so you can see them only while looking indirectly (and they "disappear" when staring at them)

Another related effect is flickering of badly designed lighting only in my peripheral vision. When looking directly at the lights they look fine, but when the lights are in my peripheral vision they appear to flash distractingly. I think the peripheral vision is optimised to detect fast changes/movements. At least, that makes sense based on evolution.

replies(2): >>43752034 #>>43773909 #
2. moebrowne ◴[21 Apr 25 13:53 UTC] No.43752034[source]▶
This is referred to as 'Averted Vision'

https://en.m.wikipedia.org/wiki/Averted_vision

3. nuancebydefault ◴[23 Apr 25 16:31 UTC] No.43773909[source]▶
The flickering i see as well when looking near my ali express outdoor LED light strip, from the corner of my eyes. The sub-components of the PWM seem to emerge as well.