Chris L Peterson wrote:
On Thu, 10 Jul 2003 09:36:17 -0400, Richard Brenz wrote:


Floaters never just "go away"...


I don't think this is universally true. Floaters have different sources, and
their lifetime in the eye varies. Floaters caused by polymerization or
crystallization of vitreous have low mobility, and may indeed remain in the
posterior chamber for a lifetime. But cellular debris has higher mobility, and
can be transported through or around the vitreous body to the anterior chamber
over a period of months to years. Material smaller than about 10u can cross the
trabecular network and leave the eye. As you know, small hemorrhages into the
vitreous can be cleared from the eye over time, and large hemorrhages can result
in glaucoma because erythrocytes/ghost cells interfere with the trabecular
meshwork.

And of course, floaters with some mobility may be carried out of the optical
path in the eye. That's pretty close to "going away." Even if the material is
still in the eye, I don't know if you could really call it a floater if it can't
be seen.
More often than not I see floaters in nearly 100% of my adult patients
and they do not complain of them.
Guess it depends on what your definition of "is" is. "Floaters" as an
ophthalmological phenomenon however usually specifically refers to
aggregates of denatured proteins. Vitreous hemorrhages and the like are
separate entities, but unfortunately too many EyeM.D.'s refer to the
symptoms as floaters. Ghost cell glaucoma is fortunately rare and an
intact zonular system(the microfibrils that attach to the capsule that
contains the lens) prevents anything much larger than single cells from
entering the anterior chamber, to gain access to the trabeculum. Often
floaters become sequestered within the vitreous, out of the line of
vision, but they nonetheless remain within the eye.


the brain selectively perceives that
they are no longer there.(Consider the physiologic blind spot where the
optic nerve enters the back of the globe...nobody sees their blind spot
but it is nonetheless there.)


That isn't my own experience. I've had a few irritating floaters for many years,
and I've never gotten used to them. The low-level cortical response to movement
is very strong- I don't see how you can get used to something that produces the
appearance of movement, especially across the fovea.
I certainly won't tell you what you experience. Each patient's mileage
may vary. I routinely tell patients that there is a good chance that
within a year, they will not notice the floaters, except under
conditions that cause miosis(small pupils). For me, it's a truism 90%
of the time.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com