I'm kind of lost here, usually I do my search on my own first but here, idk, I don't even really know what I should type in Google to look for answer.

Squarish rainbow

Basically, I got this image I generated myself and I noticed that our eyes/brain interprets/see two crossing diagonal lines.

But they do not exist. The way I generated this picture is, the inefficient way, by creating the outer square then overwriting them successively with smaller square of different colors. There is no line.

I think it might be due to proximity with other colors but I'm not sure.

Where should I ask this very question ideally?

EDIT: I got a bit inspired and search for "Brain perception lines illusion" but I haven't found my answer yet, plus I'd like an explanation on this very case if possible.

  • What would be the question you want to ask exactly?
    – Wrzlprmft
    Commented Jul 11, 2015 at 9:46
  • @Wrzlprmft Why do we see lines where there is no actual lines there.
    – jeromej
    Commented Jul 11, 2015 at 9:57
  • @Wrzlprmft (what is the scientific explanation behind it)
    – jeromej
    Commented Jul 11, 2015 at 10:06

1 Answer 1


There's a Cognitive Sciences site. Please note that it does not have many active experts.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .