# Aura or Illusion? **URL:** \ **Category:** Factual Questions\ **Created:** [September 9, 2005, 10:28pm UTC](https://boards.straightdope.com/t/aura-or-illusion/320891 "2005-09-09T22:28:53Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Thunderkiss666](https://avatars.discourse-cdn.com/v4/letter/t/f9ae1b/32.png) [@Thunderkiss666](https://boards.straightdope.com/u/Thunderkiss666)\ **Post date:** [September 9, 2005, 10:28pm UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/1 "2005-09-09T22:28:53Z")
When I stare at objects (including people),I can see an outline of light around the object with my peripheral vision.I asked someone about it and they said it was an aura.what is this light? an aura or an illusion? ---
**Author:** ![ouryL](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ouryl/32/6067_2.png) [@ouryL](https://boards.straightdope.com/u/ouryL)\ **Post date:** [September 9, 2005, 10:33pm UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/2 "2005-09-09T22:33:32Z")
See an ophthamologist :dubious: ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [September 9, 2005, 10:34pm UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/3 "2005-09-09T22:34:06Z")
Illusion. Images taken in low-light conditions with low-lux video cameras, even with image intensifiers, show no such effect. Our eyes can only see light, so you can’t explain it as some form of energy our eyes can detect that video cameras cannot, because there isn’t any such thing. ---
**Author:** ![Larry\_Mudd](https://avatars.discourse-cdn.com/v4/letter/l/f14d63/32.png) [@Larry\_Mudd](https://boards.straightdope.com/u/Larry_Mudd)\ **Post date:** [September 9, 2005, 10:58pm UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/4 "2005-09-09T22:58:45Z")
If you stare at an object and the background is lighter than the object, you will see a “halo.” This is from the combination of slip and the desensitisation of the retina. The rods that are receiving the light from the background become less receptive. The rods that are receiving the light from the object are more receptive. As your eye drifts a bit, the light from the background hits the rods that are adjusted for the lower light coming from the object. The result is that you perceive brighter light around the edge of the object, compared with the dimmed-down light being reported by the over-stimulated parts of the retina that the background light is hitting. This is totally normal – don’t worry about the ophthamologist. ---
**Author:** ![lizardling](https://avatars.discourse-cdn.com/v4/letter/l/f4b2a3/32.png) [@lizardling](https://boards.straightdope.com/u/lizardling)\ **Post date:** [September 9, 2005, 11:20pm UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/5 "2005-09-09T23:20:40Z")
OOOOH. **Larry** , you just explained what I’ve been seeing for years. In better words than, “those must be afterimages.” ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [September 10, 2005, 12:05am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/6 "2005-09-10T00:05:55Z")
> [@Larry Mudd](#): > > If you stare at an object and the background is lighter than the object, you will see a “halo.” This is from the combination of slip and the desensitisation of the retina. > > The rods that are receiving the light from the background become less receptive. The rods that are receiving the light from the object are more receptive. As your eye drifts a bit, the light from the background hits the rods that are adjusted for the lower light coming from the object. The result is that you perceive brighter light around the edge of the object, compared with the dimmed-down light being reported by the over-stimulated parts of the retina that the background light is hitting. > > This is totally normal – don’t worry about the ophthamologist. There’s an optical illusion based on this; you stare at a dark object on a mid-grey background, but because of the natural tremble of your eye, the edges appear to be glowing, because receptors are moving from dark into light and the contrast of the transition is more stimulating than the backrground colour. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [September 10, 2005, 12:48am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/7 "2005-09-10T00:48:14Z")
[Nitpick] Ophtha **L** mologist [/nitpick] ---
**Author:** ![Larry\_Mudd](https://avatars.discourse-cdn.com/v4/letter/l/f14d63/32.png) [@Larry\_Mudd](https://boards.straightdope.com/u/Larry_Mudd)\ **Post date:** [September 10, 2005, 12:49am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/8 "2005-09-10T00:49:28Z")
> [@Mangetout](#): > > There’s an optical illusion based on this… Ayuh. I’ve posted a number of demonstrations of optical illusions here that I’ve banged up in Photoshop, but I don’t think _any_ of them have been quite as easy to make as [this one](http://www.larrymudd.com/images/halo.gif). 😃 [This anomalous motion illusion](http://www.larrymudd.com/images/b3ta/hypnobsod.gif) exploits the same principle, but works with the chromatic equivalent to get yer cones to play along and create a more surprising effect. ---
**Author:** ![Thunderkiss666](https://avatars.discourse-cdn.com/v4/letter/t/f9ae1b/32.png) [@Thunderkiss666](https://boards.straightdope.com/u/Thunderkiss666)\ **Post date:** [September 10, 2005, 5:21am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/9 "2005-09-10T05:21:33Z")
wow,thank you guys 😃 ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [September 10, 2005, 5:35am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/10 "2005-09-10T05:35:48Z")
[Here’s a good one-but try not to stare at it too long, lest you give yourself a headache.](http://img.photobucket.com/albums/v220/Guinastasia/sigs/optical-illusion-wheels-circles-rot.png) ---
**Author:** ![Larry\_Mudd](https://avatars.discourse-cdn.com/v4/letter/l/f14d63/32.png) [@Larry\_Mudd](https://boards.straightdope.com/u/Larry_Mudd)\ **Post date:** [September 10, 2005, 5:53am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/11 "2005-09-10T05:53:20Z")
That’s my favourite illusion, **Guin**. I made a supersized version of it, [here](http://www.larrymudd.com/images/motion_illusion.gif). It _will_ wreck your mind. 😃 ---
**Author:** ![Larry\_Mudd](https://avatars.discourse-cdn.com/v4/letter/l/f14d63/32.png) [@Larry\_Mudd](https://boards.straightdope.com/u/Larry_Mudd)\ **Post date:** [September 10, 2005, 7:43am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/12 "2005-09-10T07:43:42Z")
BTW-- welcome, **Thunderkiss** – hope you stick around! ---
**Author:** ![jimpatro](https://avatars.discourse-cdn.com/v4/letter/j/b9e5f3/32.png) [@jimpatro](https://boards.straightdope.com/u/jimpatro)\ **Post date:** [September 10, 2005, 8:08pm UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/13 "2005-09-10T20:08:20Z")
Bloody Mary! Bloody Mary! ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [September 11, 2005, 6:09am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/14 "2005-09-11T06:09:52Z")
> [@Larry Mudd](#): > > That’s my favourite illusion, **Guin**. > > I made a supersized version of it, [here](http://www.larrymudd.com/images/motion_illusion.gif). It _will_ wreck your mind. 😃 Wahoo - I think I have found the next wallpaper for my next job\ Wonder if it would make someone seasick… 😃 ---
**Author:** ![TimeWinder](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@TimeWinder](https://boards.straightdope.com/u/TimeWinder)\ **Post date:** [September 11, 2005, 7:10am UTC](https://boards.straightdope.com/t/aura-or-illusion/320891/15 "2005-09-11T07:10:50Z")
> [@Larry Mudd](#): > > That’s my favourite illusion, **Guin**. > > I made a supersized version of it, [here](http://www.larrymudd.com/images/motion_illusion.gif). It _will_ wreck your mind. 😃 You broke my brain! I hope you’re happy.