Why does everything have an aura when I look at it?
December 5, 2004 9:40 PM   Subscribe

In good light, when I look at a blank white sheet of paper the edge of the right looks like RGB colors seperating. Red, then yellow, then the white sheet itself. If I look at the left edge, it appears slightly blue. What is wrong with me?
posted by Keyser Soze to Health & Fitness (12 answers total)
Can we assume this is something you've always had, or is it a new development?
posted by dhartung at 10:26 PM on December 5, 2004

You may be experiencing the McCollough Effect. Have you tried online tests for color blindness?
posted by fatllama at 10:31 PM on December 5, 2004

there isn't enough time in the world to adaquately answer your actual question.

As for the colors and the paper, is it possible it has something to do with the lighting in the room you're in?
posted by crunchland at 10:32 PM on December 5, 2004

I presume you're not wearing glasses? High index lenses (that is, really strong prescriptions that are made ulta-thin so they'll fit in glasses frames better) sometimes do this, splitting out red and yellow on one side, and light blue and purple on the other, sorta prism-like. You can sometimes see it in the outside corners of your eyes, especially when viewing reflected light in glass windows.

(This kept me entertained through many a high school history class.)

If you're not wearing glasses, can we call you "ole prism eyes"?
posted by Asparagirl at 10:35 PM on December 5, 2004

sounds like chromatic aberration of some kind - a lens (either glasses, contact lenses, or your cornea) is focussing different colours of light to slightly different positions. try looking in different directions - you'll probably find that it varies in strenght. i see it particularly if i look down through the bottom of my glasses.

this is normal - in fact it's a standard problem in designing things like telescopes or camera lenses - as long as it's not so large it's noticeable all the time. you're seeing it particularly with the edge of a white sheet because (1) white is made up of all the colours (if it was a single colour, then you wouldn't get the problem because it would be focussed to a single point) (2) the straight edge is a simple high-contrast image that makes it easier to see (less detail to confuse things).

of course, i can't tell if your particular case is normal - if you're worried, see an optician (i'm just a physicist (or was)) - but my theory is that people generally don't notice this partly because it's a small effect, but also because our brains are amazingly good at processing images and so normally we don't realise just how bad our eyes are as optical systems.

(from the way the physics works you'll find that the colours are in the order of the rainbow (or backwards)).
posted by andrew cooke at 2:19 AM on December 6, 2004

thinking some more about this, i think it's much more likely with glasses, looking near where the frame is, than anything else, because you have to be looking off-centre (unless you're astigmatic, i suppose).
posted by andrew cooke at 3:58 AM on December 6, 2004

Since you qualified the kind of paper that causes this phenomenon, I'd first eliminate the paper as the cause by flipping it over and look at the reverse side to see if the red/blue right/left edges are in relation to you or the paper.
posted by Jeff Howard at 6:21 AM on December 6, 2004

That's what happens with my glasses, because they are damn high-index (like Asparagirl said). Don't worry, it's just some goofy refraction going on. And it's vaguely amusing to be able to tell that "yellow" light is really "red plus green."
posted by jenovus at 10:01 AM on December 6, 2004

Fatlama, et al: thanks for that color blindness test. The last one suggests I have a borderline color problem...
posted by ParisParamus at 10:30 AM on December 6, 2004

I've noticed that in my hottub, anything underwater is colour-fringed. I'm pretty sure it's to do with index of refraction and all that jazz. I'm surprised you're seeing it easily in air.
posted by five fresh fish at 12:28 PM on December 6, 2004

I suffer from keratoconus, but in my case this manifests as almost pure astigmatism (ie cylindrical distortion of the lens) and very little near/far-sightedness (ie spherical distortion). The effect you describe sounds like a pretty exact description of "coma" that is caused by astigmatism. Do you see this effect on headlights on distant car headlights at night?

Either way, I agree with what others have said here - time to see an optician or ophthalmologist.
posted by kcds at 2:49 PM on December 6, 2004

Response by poster: Yup, it was the glasses all along. I've been tweaking my poor monitor for months. Goddamn, I didn't realize my eyes are that bad. I have the option of wearing contacts so maybe its not terrible, but bad.
posted by Keyser Soze at 8:43 PM on December 6, 2004

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