Optical reflections

[cdave]

Big thanks to major_clanger for inviting me to a talk on invisibility at the IET. It was actually about the new materials with interesting optical properties, that don't exist in nature. His write up is worth a read.

I've tried to find some copies of the ray diagrams from the slide show to illustrate the fantastic properties of this stuff (if you made a milk bottle from it, you would see the milk outside the edge of bottle), but couldn't find any online. If I get time, I'll write them up from memory.

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chiller has found what causes the squigly things you see when you look up at clear blue sky.

It reminded me of an odd visual distortion I've noticed a few times.

If you press you palms to your closed eyes, applying a light pressure simulates the retina. When I do this I see sort of yellowy-greenish-purple blobs. It wasn't until I tried to photoshop the image you'll see below that I realised this is the colour of magic and being made up from opposite sides of a colour wheel shouldn't exist e.g. (red+green = white, blue + orange = white, yellow+purple=white, etc).

To get the point, I've noticed that I occasionally, when having a shower in the morning, and I'm scrunching my eyes up to stop soap getting in them, I see an Phosphene that looks a bit like this:


It gets brighter the longer and tighter I screw my eyes up. If I leave them closed long enough I even get afterimages. Never happens at any other time.

Anyone else have any intersting visual distortions?

Being a Friday Afternoon I doubt there's many LJ readers out there, but thought I'd ask just in case

Comments

[hairyears.livejournal.com]

When I'm very tired, my peripheral vision gets flashes and an illusion of the roiled air turbulence one observes over a very hot object.

[cdave]

Interesting.

I know my eye sight gets worse when I'm tired. I also get a little quesey when I put on curved sunglasses as they mess with my peripheral vision. So I'm quite glad I don't get this one.

[chiller.livejournal.com]

I love it when people blog inconsequential, but intensely personal stuff like this.

When I was a very small kid I used to get a lot of random nerve action in my eyes after dark, which was like lying in the middle of a slow firework display. It was brilliant. I still get some, but it's much reduced.

Not related, but fun: quite often when I'm dropping off to sleep, I think my eyes are open when they are actually closed. I lie there thinking I am looking at my bedroom, and at some point realise that it must be nonsense, because my eyes are shut. At that point I start really enjoying it and looking around.

[cdave]

Ooh, I get that one sometimes. In a nearly black room slowly close your eyes and you suddenly realise that your eyes are shut, but you can still see the outline of the shelves.

[chiller.livejournal.com]

Oh, what a relief! I thought it was just me ...

[cdave]

Have you checked it's not actually X-ray vision





cos I have, and it isn't :(

[chiller.livejournal.com]

Well, I'm not sure how to. I mean: it's a room, in the dark. Nothing moves ... so it might be X-ray vision! Gosh I hope so.

Although if the only thing I can see through with my superpower is my own eyelids, that's a bit lame and I don't think I'm going to go bragging about it at the next big superhero meet-up.

[fiat-knox.livejournal.com]

I have seen the same transient visual phenomenon against a featureless blue sky. I've also seen a swirling moire pattern on a hot day, when I was on the verge of a heatstroke; and the same kind of visual distortions when I've pressed my eyes gently in the morning.

I also get a visual distortion effect of a red and black flickering when I'm heading into town on the bus, in the sunlight, and the light shines through the trees along the sides of the road at a certain speed. That's not such a pleasant effect. I get a headache by the time I get into town.

[cdave]

Erk. Yeah, lights through trees when moving really fast aren't great. Doesn't give me red flashes though.

Ooh, does remind me of another one though. Sometimes when my green indicator lights areflashing on the dashboard, I see them as blue flashes in my peripheral vision. This is the colour of the highbeam light, so I keep looking down to make sure I'm flashing the driver in front.