Can any of you smart people out there tell me what causes eye "floaters?"
I mean the little specks and swirls (looks kind of like a film) that seem to
float around "in front of" the eye?
Can any of you smart people out there tell me what causes eye "floaters?"
I mean the little specks and swirls (looks kind of like a film) that seem to
float around "in front of" the eye?
In an article of <5 Dec 89 19:40:42 GMT>, ham…@sp12.csrd.uiuc.edu (David
Hammerslag) writes:
DH>Can any of you smart people out there tell me what causes eye
DH>"floaters?"
DH>I mean the little specks and swirls (looks kind of like a film) that
DH>seem to
DH>float around "in front of" the eye?
DH>
The back portion of the eye (posterior chamber) is filled with a gel body
called the vitreous, which has the consistency of and is very much like – the
white of an egg. When you examine an egg-white, you no doubt have observed
that there are – on occasion – strands of material within in it that are white
as opposed to clear. These are condesations of the egg-white. The same sort
of thing happens within the vitreous of the eye. These strands – being more
dense are also more opaque and cast shadows upon the retina – which you
observe.
Being denser, they tend to gradually sink to the dependent part of the eye – a
process that can take many years. As you get older, the vitreous shrinks and
pulls away from the retina and fluid accumulates between the two. The vitreous
then becomes more mobile (syneresis) and rotates with each movement of the eye
and/or body. This can cause these particles and strands to move around within
the eye (kind of like the snow scenes in a globe that you shake and watch the
snow fall).
This movement of the vitreous is also the cause for another phenomenon called
"entopic phenomenon" or lightning flashes in the peripheral vision, especially
in the evening or early morning hours. The vitreous, moving across the retina,
generates an electrical charge within the nerve fiber layer. Impulses
generated in this layer are typically bluish-white, arcuate in form and of very
short duration – hence the "lightning flash."
Leo Bores, M.D.
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Dust on the eyeball? Affected by gravity? Always float down?
Are these floater things the same things i see when i stare hard into space
or at a white surface? They look like specks of dust or pieces of hair
flaoting around…..
Also, why do yousee colors when you rub your eyes?
-elisha
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In an article of <6 Dec 89 14:53:44 GMT>, r…@hpcilzb.HP.COM (Roger Haaheim)
writes:
RH>Dust on the eyeball?
Condensation of the vitreous gel within the ye.
RH>Affected by gravity?
More dense than the surrounding medium.
RH> Always float down?
Not always and "float" may not be the best term except that they do not sink
rapidly but slowly in a manner that suggest floating or wafting.
Leo
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In article <9198.257DE…@stjhmc.fidonet.org> Leo.Bo…@f14.n114.z1.fidonet.org (Leo Bores) writes:
>This movement of the vitreous is also the cause for another phenomenon called
>"entopic phenomenon" or lightning flashes in the peripheral vision, especially
>in the evening or early morning hours. The vitreous, moving across the retina,
>generates an electrical charge within the nerve fiber layer. Impulses
>generated in this layer are typically bluish-white, arcuate in form and of very
>short duration – hence the "lightning flash."
Is it true that these "lightning flashes" can be a symptom of retinitis
pigmentosa, or are these different?
In an article of <8 Dec 89 18:25:21 GMT>, elw…@cfa250.harvard.edu (Elwood)
writes:
EA>Are these floater things the same things i see when i stare hard into
EA>space
EA>or at a white surface? They look like specks of dust or pieces of hair
EA>flaoting around…..
Yes
EA>Also, why do yousee colors when you rub your eyes?
EA>-elisha
When you rub your eyes you produce extremely high pressure on the retina and
optic nerve. It responds by sending electrical signals to the brain which are
interpreted as various colors.
Leo Bores, M.D.
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In article <9198.257DE…@stjhmc.fidonet.org>, Leo.Bo…@f14.n114.z1.fidonet.org (Leo Bores) writes:
<The back portion of the eye (posterior chamber) is filled with a gel body
<called the vitreous, which has the consistency of and is very much like – the
<white of an egg.
<As you get older, the vitreous shrinks and
<pulls away from the retina and fluid accumulates between the two. The vitreous
<then becomes more mobile (syneresis) and rotates with each movement of the eye
<and/or body.
<This movement of the vitreous is also the cause for another phenomenon called
<"entopic phenomenon" or lightning flashes in the peripheral vision, especially
<in the evening or early morning hours. The vitreous, moving across the retina,
<generates an electrical charge within the nerve fiber layer. Impulses
<generated in this layer are typically bluish-white, arcuate in form and of very
<short duration – hence the "lightning flash."
Is this also the reason for "red flashes"? I sometimes see a "red flash" as
an individual, very short-lived (like a couple tenths of a second) tiny red
dot, like a red L.E.D., in my main visual area. Since they aren’t "arcuate"
as you describe for "lightning flashes," nor are they in the peripheral area,
I wonder what they could be, if not the vitreous rubbing against the retina.
Something knocking into the retina, like particles inside the eye? Or cosmic
rays maybe?
—
Daniel R. Levy UNIX(R) mail: att!ttbcad!levy, att!cbnewsc!levy
AT&T Bell Laboratories
5555 West Touhy Avenue Any opinions expressed in the message above are
Skokie, Illinois 60077 mine, and not necessarily AT&T’s.
Could they be hemorrhaging blood vessels at the back of the eye? This
sometimes occurs as a person gets older.
I quote from "The Merck Manual", 14th edition:
Retinal hemorrhages are always significant, reflecting
vascular disease that usually is systemic.
Disclaimer:
Since I am not a doctor, I am not prescribing any course of action for you to
take, merely passing along information.
End of Disclaimer:
If I were you, I might want to get this checked out.
In a message of <09 Dec 89 17:44:00>, John Moe (1:231/80) writes:
JM>My friend said that her floaters heralded retinal detachment and she
JM>warns to take them seriously. My opinion is that they are pretty
JM>common and mostly non-serious, but of course your friendly neighborhood
JM>ophthalmologist no doubt looks into your eyeballs once a year, right??
JM>(signed) John Moe
Sometime in the distant past, some great king died shortly after his
astronomers discovered a comet in the sky. For centuries after that – comets
were said to be bad omens and all sorts of dire things were predicted upon
their appearance.
Therefore, while your friend’s RD (retinal detachment) may well have been
heralded by the sudden appearance of floaters – that relationship is not a
given. Many more individuals have floaters than have RD. My advice to patients
is to have an exam when the floaters first appear or if the onset is sudden or
associated with lightning flashes. If after the initial exam the floaters get
worse or the vision decreases or a "curtain" comes down over your field of view
– get another exam. In the latter case – the same day.
Leo Bores, M.D.
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In an article of <11 Dec 89 21:02:59 GMT>, l…@cbnewsc.ATT.COM (Daniel R.
Levy) writes:
DR>Is this also the reason for "red flashes"? I sometimes see a "red
DR>flash" as
DR>an individual, very short-lived (like a couple tenths of a second) tiny
DR>red
DR>dot, like a red L.E.D., in my main visual area. Since they aren’t
DR>"arcuate"
DR>as you describe for "lightning flashes," nor are they in the peripheral
DR>area,
DR>I wonder what they could be, if not the vitreous rubbing against the
DR>retina.
DR>Something knocking into the retina, like particles inside the eye? Or
DR>cosmic
DR>rays maybe?
I suppose that cosmic rays could be the cause – they’re blamed for almost
everything these days and it is true that some experimenters suspect them. I
suspect, however, that these spots are a variation of the "phosphene of quick
eye movement" which is typically a yellowish-orange in color.
Leo
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Leo.Bo…@f14.n114.z1.fidonet.org (Leo Bores) writes:
>This movement of the vitreous is also the cause for another phenomenon called
>"entopic phenomenon" or lightning flashes in the peripheral vision, especially
>in the evening or early morning hours. The vitreous, moving across the retina,
>generates an electrical charge within the nerve fiber layer. Impulses
>generated in this layer are typically bluish-white, arcuate in form and of very
>short duration – hence the "lightning flash."
Interesting. I have had these intermittently the past couple of
years, almost always late at night when walking the dogs (my first
exposure each day to nearly complete darkness). I had always
associated them with fatigue, since they seemed more likely to occur
if I was (or my eyes were) pretty tired.
I take it this is a pretty normal phenomenon (for someone in late 30s
to 40).
/JBL
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or {…}!bbn!levin |
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In an article of <13 Dec 89 07:02:44 GMT>, e…@khijol.UUCP (Edwin R. Carp)
writes:
ER>Could they be hemorrhaging blood vessels at the back of the eye? This
ER>sometimes occurs as a person gets older.
Retinal hemorrhages do not manifest in that way. If they are associated with
scarring and retinal retraction – then white flashes will be seen.
Leo Bores, M.D.
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From article <1989Dec5.194042.20…@ux1.cso.uiuc.edu>, by ham…@sp12.csrd.uiuc.edu (David Hammerslag):
> Can any of you smart people out there tell me what causes eye "floaters?"
I have floaters from an accident that occured while I was in a fire department
) anchored-down deck gun. A tear in my retina,
training session. I was struck in the eye by a 1 3/4" dia. 175 psi stream of
water from a (supposedly
which could have resulted in blindness, was ‘spot-welded’ in place by
cryo-surgery (sic?). The floaters are blood that is suspended in the clear
fluid in my eye. Mine don’t bother me unless I’m very tired, or I quickly go
from a dimly lit room to bright sunlight.
If you don’t know where yours came from, I would see an eye doctor SOON.
—
Tom Ohmer @ Defense Logistics Agency Systems Automation Center,
DSAC-AMB, Bldg. 27-6, P.O. Box 1605, Columbus, OH 43216-5002
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Phone: (614) 238-9210 AUTOVON: 850-9210 Disclaimer claimed
And isn’t it true that cosmic rays cause cancer in laboratory rats?
in article <2…@rruxc.UUCP>, w…@rruxc.UUCP (W W Scott) says:
> I remember a short discussion about floaters in a course about 10 years ago.
> I think they are dead cells inside the eye that are floating around in
> the fluid.
I’ll agree to that. I used to spend many hours at a microscope, and
the way the light shown, I could see red blood cells floating around in my
eye.
–
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AT&T Bell Labs, Denver; (303)538-4800
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