21 replies to this topic

[Ourmoonlitsun]

Papaver on Mar 16 2008, 06:05 PM, said:

Here's a description of how they usually appear to people and what they are all about.

Floaters aren't noticeable all the time. When your eye is still or you are gazing into space, you may see them drift slowly across your vision. When you move your eye to look in different directions, floaters tend to move quickly. They don't follow your eye movement precisely and seem to dart away as you try to look at them.

Floaters may appear as dots, circles, lines, cobwebs or other shapes. They are usually grey and semi-transparent. Most floaters are small and quickly move out of your field of vision.


Here is a link to the British National Health Service websibe with an article on them.

http://www.nhsdirect.nhs.uk/articles/artic...amp;sectionId=1

They are not the same, but they may appear similar.  Floaters are made up of broken down tissue.  They tend to move with the eye, as you stated, and generally appear in the same area of vision, though they do "float."

Blue field entoptic phenomenon, on the other hand, is different in that all these lights follow squiggly paths across the eye--some paths run horizontal, some vertical, some diagonal.  It really can come to look like a grid.  

So, yeah, it could be floaters, but with floaters you usually only have one object in your vision--or more if you have more floaters, but they don't necessarily follow each other along paths; if you stopped moving your eyes they should settle.  With blue field entoptic phenomenon, because it is actually white blood cells you are seeing, even if you don't move your eyes you will see pronounced movement as the cells follow one another along specific, squiggly paths along the surface of your eye.

The two do get confused much

[eight bits]

Well, floaters are pathological (although only "seriously" so in a tiny fraction of cases).

Scheerer's is normal. Although doubtless if any of us were God, we would have done it differently, much of the blood vesel support which keeps the retina alive is between it and the lens.

And neither is a hallucination - what you see is really there.

But if you want a bit of hallucination, it's not too hard. What you experience visually is already almost a hallucination, but one that happens to get it right most of the time.

At any given moment, the signal being piped down your optic nerve is a witch's brew of actual scene, haphazardly registered afterimages, neurons misfiring for no particular reason, neurons firing to encode visual features in special ways, ... a noisy signal, or signally noise.

And then, supplied with this bundle of misinformation, your brain goes to work and creates a stable visual world, with color, detail throughout the scene, movement (usually) well depicted, your own movements duly edited out, etc., in something respectably like real time.

Want to see something different, then? The relationship between what you experience and what the eye reports is so tenuous anyway, misperception is like shooting fish in a barrel. Just look at anything for a while with what would be modestly rude stare. Don't blink too much, or else blink way too much.

The scene destabilizes, because the processing machinery starts slipping. You can get granules, threads, tubes, afterimage persistence, all kinds of vaguely weird stuff.

A child could do it.

In a manner of speaking, of course.

[Shadow Huntress]

Quote

Floaters may appear as dots, circles, lines, cobwebs or other shapes. They are usually grey and semi-transparent. Most floaters are small and quickly move out of your field of vision.

That's not what they're like at all. They're like miniscule white dots that zap around everywhere, bouncing off objects and they don't come in and out of my vision, they've always been there (and don't say it's my eyesight now, because I've got perfect eyesight). There's more of them around plants and humans and stuff.

[eight bits]

Hi, Shadow Huntress.

Quote

and don't say it's my eyesight now, because I've got perfect eyesight

Then you do not have floaters, since they are a pathological condition.

What you report sounds like you see some of the bloodflow which supports the retina. That is normal. Scheerer's makes the phenomenon compelling, but the bloodflow itself is always there to be seen.

The visual noise appears to be "around" objects probably because you are "looking at" the objects, rather than the space around them. There is no obstructive vasculature in the small region of the retina (the fovea) we use to "look at" something.

People differ considerably in how much they "clean up" their raw visual input when creating the visual scene. Many people simply ignore the raw input and attend to the scene. For example, few people notice routine eyeblinking, or blurring during the larger saccades (lurches of the eyeball from one place to another), or that most of the visual field is out of focus when they look at one specific thing.

You, apparently, like a little visual noise around your objects. No worry.

[bleedingelite]

eight bits on Mar 16 2008, 03:18 PM, said:

Well, floaters are pathological (although only "seriously" so in a tiny fraction of cases).

Scheerer's is normal. Although doubtless if any of us were God, we would have done it differently, much of the blood vesel support which keeps the retina alive is between it and the lens.

And neither is a hallucination - what you see is really there.

But if you want a bit of hallucination, it's not too hard. What you experience visually is already almost a hallucination, but one that happens to get it right most of the time.

At any given moment, the signal being piped down your optic nerve is a witch's brew of actual scene, haphazardly registered afterimages, neurons misfiring for no particular reason, neurons firing to encode visual features in special ways, ... a noisy signal, or signally noise.

And then, supplied with this bundle of misinformation, your brain goes to work and creates a stable visual world, with color, detail throughout the scene, movement (usually) well depicted, your own movements duly edited out, etc., in something respectably like real time.

Want to see something different, then? The relationship between what you experience and what the eye reports is so tenuous anyway, misperception is like shooting fish in a barrel. Just look at anything for a while with what would be modestly rude stare. Don't blink too much, or else blink way too much.

The scene destabilizes, because the processing machinery starts slipping. You can get granules, threads, tubes, afterimage persistence, all kinds of vaguely weird stuff.

A child could do it.

In a manner of speaking, of course.

So, basically, everything we see with our eyes is suspect to begin with?

[eight bits]

Quote

So, basically, everything we see with our eyes is suspect to begin with?

Yes, but "suspect" is a little bit strong.

Think of it like a "docudrama." What you're seeing is intended to be "just like" the real events, except when the producers get it wrong. Some producers get it wrong more often than others, and every producer makes some mistakes now and then.

[bleedingelite]

eight bits on Mar 25 2008, 09:42 AM, said:

Yes, but "suspect" is a little bit strong.

Think of it like a "docudrama." What you're seeing is intended to be "just like" the real events, except when the producers get it wrong. Some producers get it wrong more often than others, and every producer makes some mistakes now and then.

Sweet, so there's a little blinking "Dramatization" at the bottom of my field of vision.

I used to think about this:

vision - Light takes time to travel to your eyes and be processed by your optic nerve.
Touch - the electrical impulses take time to travel through your nervous system
Smell - aromas travel much more slowly than light
Taste - must be processed by taste buds
Hearing - Soundwaves must travel to your ear, speed of sound is slower than light

So, basically, our sensory input is at any one instant composed of 5 very recent points in the past. So that means that the reality which we interpret through our senses isn't really reality, or something. Right?