# Explain this 3D optical illusion I see with green/red text

**URL:** <https://boards.straightdope.com/t/explain-this-3d-optical-illusion-i-see-with-green-red-text/678322>\
**Category:** Factual Questions\
**Created:** [January 8, 2014, 10:45pm UTC](https://boards.straightdope.com/t/explain-this-3d-optical-illusion-i-see-with-green-red-text/678322 "2014-01-08T22:45:45Z")\
**Posts on this page:** 3\
**Page:** 3

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**Author:** ![TubeAmp](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@TubeAmp](https://boards.straightdope.com/u/TubeAmp)\
**Post date:** [July 13, 2014, 3:55pm UTC](https://boards.straightdope.com/t/explain-this-3d-optical-illusion-i-see-with-green-red-text/678322/41 "2014-07-13T15:55:42Z")

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> [@Bryan\_Ekers](#):
>
> An obsession with Canadian sitcoms?

Good answer… but there was no mention of Duct Tape, so I would rule that out.

T A

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**Author:** ![TubeAmp](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@TubeAmp](https://boards.straightdope.com/u/TubeAmp)\
**Post date:** [July 13, 2014, 3:57pm UTC](https://boards.straightdope.com/t/explain-this-3d-optical-illusion-i-see-with-green-red-text/678322/42 "2014-07-13T15:57:25Z")

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> [@cmyk](#):
>
> To clarify a bit more on my above post:
> 
> One lens is most likely refracting the image a bit more than the other (let’s say the right eye for instance), causing the color green to appear shifted more than red relative to your left eye.
> 
> This discrepancy in shifting of particular colors over others, combined with one lens giving you a slightly different image than the other, creates the illusion of depth when your right eye merges the image from your left eye, depending on the particulars of the optics, your eyes, and the wavelengths involved.

I can see it with one, or the other eye, or both… so it has nothing to do with stereo-optics.

T A

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**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\
**Post date:** [July 13, 2014, 4:00pm UTC](https://boards.straightdope.com/t/explain-this-3d-optical-illusion-i-see-with-green-red-text/678322/43 "2014-07-13T16:00:50Z")

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To me, it looks the opposite – the red is closer the green further back. I also have vision in only one eye.

But to me, the red is darker and more vivid, and as any painter knows, objects in the background are less contrasted than those u p close, so my eye is telling me the less contrasty green is further wway.

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