Conversation

Notices

1. Embed this notice
   Kim Scheinberg (kims@mas.to)'s status on Monday, 02-Mar-2026 06:31:10 JST Kim Scheinberg

   This is a very cool optical effect

   Whichever dot you focus on looks purple while the others look blue

   As someone whose eyes have been "settling" from cataract surgery followed by a superficial keratectomy in one eye, and has noticed my vision changing daily at various focal points, this is fascinating

   https://arxiv.org/pdf/2509.11582v2

   • Embed this notice
     Kim Scheinberg (kims@mas.to)'s status on Monday, 02-Mar-2026 08:27:59 JST Kim Scheinberg

     in reply to

     • Toilet full of bugs

     @ephemeromorph
     I read the paper but am not smart enough to understand why it would not work on certain people

   • Embed this notice
     Toilet full of bugs (ephemeromorph@topspicy.social)'s status on Monday, 02-Mar-2026 08:28:01 JST Toilet full of bugs

     in reply to

     @kims I don't get this illusion at all! I thought it might be because I'm on PC and the image dimensions make me think it's meant to be shown on a phone screen, so I zoomed out. Still all looks purple. I can't make myself see any blue!

   • Embed this notice
     Steve Gisselbrecht (stevegis_ssg@mas.to)'s status on Tuesday, 03-Mar-2026 01:47:46 JST Steve Gisselbrecht

     in reply to

     @kims

     This is cool because I'm colorblind enough to struggle with distinguishing purple and blue, and all the dots look reliably the same color.

   • Embed this notice
     Greg Whitehead (grwster@mastodon.social)'s status on Wednesday, 04-Mar-2026 11:19:31 JST Greg Whitehead

     in reply to

     @kims Interesting. I’m red/green colorblind and initially wasn’t seeing the effect, but then I looked at the paper and saw that it’s a distance-dependent illusion, best seen at 30cm (about 12in). At that distance I DO see it faintly

   • Embed this notice
     JanetD (jcdvore@mas.to)'s status on Wednesday, 04-Mar-2026 13:43:09 JST JanetD

     in reply to

     @kims I don't see blue dots, but if I quickly scroll the page up or down, I briefly see shadows of the dots.

   • Embed this notice
     Kim Scheinberg (kims@mas.to)'s status on Wednesday, 04-Mar-2026 16:15:11 JST Kim Scheinberg

     in reply to

     • Clive Thompson
     • Kieran Healy

     @clive
     If I were still speechwriting, this would be a slide in a future presentation. There are so many metaphors contained in this

     I'll be almost disappointed if it doesn't appear in a @kjhealy talk sometime in the next year or two

   • Embed this notice
     Clive Thompson (clive@saturation.social)'s status on Wednesday, 04-Mar-2026 16:15:13 JST Clive Thompson

     in reply to

     @kims

     this is wild!