Weird visual things

So, I have weird eyes and weird vision. I may have mentioned this before, but I’m going to go into a bit more detail. I’m not claiming any of these things are pathological. They’re mostly things I’ve always had and generally perceive as ‘normal’. I have no idea how prevalent they are generally.

Oh, and if you have migraines with auras, please read this because I’d appreciate your comments on a few things. (I don’t have migraines, but a couple of these things sound similar to migraine auras).

[Quick warning: There will be a small, but very flickery animated gif further down.]

Possibly a Squint

We’ll start off with the one thing that’s been medically observed. This is my possibly-a-squint. I’ve thought of it as a squint, because that’s how the optometrist described it when I was 17, but I think there may have been some over-simplification going on.

Anyway, I first noticed my probably-not-really-a-squint when I was 17. I was working in a shop and getting headaches from the way that changing focal distances (ie. looking up from the till). For a couple of moments, my eyes wouldn’t focus properly, so I’d see double. The two images would very quickly move together and fuse into normal vision. It happened most often when I was tired and was kind of annoying.

The optometrist did the various tests and came up with the squint diagnosis. I think, however, he was simplifying things a little. Most types of strabismus are obvious – the eyes don’t line up. I don’t have that. What I think he was saying is that I have a ‘latent squint’. One or both eyes doesn’t automatically line up the right way with the other and my brain has to tell the eye to focus properly. It’s compensated, in other words. I have a tendency to read with one eye closed and when I get up, if I’m particularly tired, I won’t be able to keep both eyes open at the same time for half an hour or more. If I’m not tired and pay attention, I’ll notice that it takes me a moment or two to focus, but mostly I’m not conscious of the process (my visual system probably blanks out the input from one eye directly after I refocus).

Visual Snow

This has been around for a while and it’s another thing I don’t really notice consciously. I’m still not sure if I’m right in calling it visual snow, because I don’t really have anything to compare it to. On balance, I think it’s probably not something everyone experiences, so I’ll go ahead and describe it.

Imagine looking at the world through a kind of haze of static. A bit like a TV not quite tuned in to the station. It’s particularly noticeable against dark objects and pretty much everything in dim lights. Things that are naturally complex (trees, for example) aren’t really affected. But it’s also very evident against bright objects like an overcast sky (a cloudless sky has its own visual effects, but those are ones I share with everyone to a large extent).

It doesn’t really impede my vision. It doesn’t get in the way, normally. Sometimes it does become more extreme. It tends to be worse if I’m under a lot of stress. For example, at the beginning of the year when I was doing a lot of sitting in waiting rooms feeling rather crazy, it was very noticeable. When I was taking citalopram it would become quite impairing when I was heading towards a crash in mood. I described it to my doctor as being unable to do much except sit back and watch my ceiling dissolve into static.

Swirly things

You get pictures for this one:

This is something that happens very occasionally, for no apparent reason. I can be walking along, and suddenly my visual field will be filled with these things, maybe 20 of them all spinning in place. They appear to be directly in front of me, perhaps a meter or two away. They last for up to a minute, then disappear. It’s been suggested that this might be retinal detachment (which would be bad), but as I understand it, that’s characterised by flashes from the edge of the visual field rather than things swirling around in front of you. Plus, I’ve been having them since I was 10 or 11 and nothing was picked up by the optometrist who did my eye test.

So, I have no idea what causes them and if anyone can suggest anything I’d love to hear it.

Flickering lines

This is one thing I’m interested in hearing about from people who have migraines. Now, I don’t have migraines, so I’d like to know if this is something that you might experience during an aura.

Occasionally, lines will flicker drastically for no apparent reason. The effect is particularly pronounced with paving slabs, but while it’s happening anything I’m looking at which has a regular pattern of lines will flicker. If I keep my vision perfectly still nothing happens, but moving my eyes across a surface (as you do, if walking over paving slabs) does it. It’s kind of like scanlines slowly moving down a display; very visually active.

Apart from being distracting, it’s not really a problem. It’s just… odd. I used to notice it quite a lot when I was walking to university, but it didn’t seem to have anything to do with light conditions or anything except me.

Now this sounds similar to symptoms I’ve heard migraine sufferers talk about. Obviously not the main one, because the headache from hell must take up quite a lot of your attention. Feel free to tell me I’m talking crap if that’s what I’m doing.