[digitalengineer]

You are correct: Floaters are normal. Fixed spots are not. Floaters, well they float. You can easily see the difference when you look left and quickly look right. Floaters keep moving a bit because of the motion. Try it in front of a clear blue sky or white wall for best results.

[3A2D50]

Floaters can be a real annoyance. I managed to damage my right eye from over focusing four months ago. I now have a brown floater that takes up about 5% of the right eye's vision. Fortunately it doesn't settle directly in my line of focus, but manages to swing by when I shift my vision. Very distracting. It becomes very noticeable in daylight, as it appears that there are many fine threads connected to it that span the lower quarter of my vision.

[stephen_g]

Wow, I get this, but very minor (the bits are mostly transparent and really small, but I can see them looking at the sky). I didn't know for sure whether they were physical objects or something in my mind, but they way they moved made me think they must be physical. Good to know that's actually a thing!

[dchichkov]

These are white blood cells moving in the capillaries in front of the retina of the eye.

[norswap]

Those are simply nerves that run in the eye, everyone has them.

[stan_rogers]

They're often just very small dust particles and minor variations in the thickness of the fluid coating the cornea as well. Those would be the ones that seem to float gently downward (sometimes almost forcing you to try to follow them, which is, of course, impossible) but which tend to reestablish their position after every blink. Annoying, but that's all.

[pja]

IIRC the really small white ones that you see when looking up at a blue sky are actually white blood cells in the arteries on the inner surface of your eyeball.

[heed]

It's called 'blue field entoptic phenomenon.'

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

[iceron]

Yes, Blue field entoptic phenomenon is the name.

I've also heard of visual snow, which seems to be related to migraines.

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

http://f1000.com/posters/browse/summary/1090714