You're making excuses for the things you've never done

[venta]

Today's foolish experiment:

Look at the sun, or a lightbulb, or something brightish. Use common sense, please do not blind yourself.

Now close your eyes, or put your hands over your eyes, and you should see the bright after-image.

What does this image do? Does it stay still, does it drift? I keep observing that my after-images always drift to the right. I have no idea if this is significant of anything in the slightest.

Be my data points, darlings...

Comments

[cardinalsin.livejournal.com]

If it drifts, that means your eye is moving, since the afterimage is a result of retinal bleaching. Unless your retinas are loose, of course. But that wouldn't be a good thing.

[chrisvenus]

I've noticed the movement phenomenon and I think its because if the image is offcenter you try to look at it and your eye moves right and then its more to the right so your eye moves more right. As far as your eye is concerned it isn't moving but your brain knows your eye is moving so concludes that the image is too... That's what I've deduced after hours of thinking about it. :)

[cardinalsin.livejournal.com]

Sounds eminently plausible. Possible test for this: stare at light bulb then consciously point your eyes to the extreme right (or left, it doesn't matter - as long as you're looking hard in one direction). That should overwhelm the natural tendency to track the afterimage. Therefore, if your theory is correct then this test will generate a stationary afterimage.

[floralaetifica.livejournal.com]

Just what I was going to say. It's the same with floaters.

[chrisvenus]

LOL. And I was about to say that too. :)

I decided the mechanics of floaters was probably a bit more complicated though... Maybe...

[cardinalsin.livejournal.com]

I thought floaters *were* afterimages. No?

[chrisvenus]

Nah. They are bits of crap floating around in your eye...

http://en.wikipedia.org/wiki/Floater

[cardinalsin.livejournal.com]

Oh, those.

Cool wikipedia article. Slightly sinister-sounding:
"Floaters are essentially changeless, and the most prominent continue to be seen in the field of vision for a lifetime."

[chrisvenus]

They're even more scary when your optician asks if you are seeing more of them because its a sign that your retina is detaching. Its amazing how much more you notice them after somebody has told you that. :)

[venta.livejournal.com]

Hmm, yes, that makes sense. I shall now upgrade to being puzzled about why I naturally look to the right when my eyes are shut...

[onebyone.livejournal.com]

Totally made-up theory: if you had a very slight squint, then the after-image couldn't be centred in both eyes at once.

Alternatively, could it be related to vertigo, and the image isn't moving at all, your brain is just confused by lack of spatial context? After a few instalments of PintWatch, does the room spin clockwise or anti-clockwise?

[venta.livejournal.com]

After a few instalments of PintWatch, does the room spin clockwise or anti-clockwise?

I have no idea. I shall make it primary research project for this weekend.

I had wondered whether the drift of my after-images was because I'm astigmatic, but my knowledge of astigmatism is sufficiently shaky that I've no idea if that's plausible. Must go and read up on it, really - my only real interactionwith it is it puts some extra numbers on my lens prescription at the opticians.

[bateleur.livejournal.com]

With practice you can control the motion.

(This information c/o some very boring history lessons around 25 years ago.)

[venta.livejournal.com]

For a moment there I thought you must have had surprisingly creative history lessons if you were taught that. Then I caught up ;)

[thefon.livejournal.com]

I was going to say that. Mine basically stay in the centre (with a bit of wobble) but I can make them go left or right.

Some people think looking to the left or right could indicate lying or remembering: http://www.blifaloo.com/info/lies_eyes.php