By
Jonathan Yoken, MD
FLASHES
AND FLOATERS
What are
floaters?
The small
specks or "bugs" that you may occasionally see moving
across your vision are called floaters. They are most visible
when you are looking at a plain background such as a white wall
or the bright blue sky. Floaters are actually tiny clumps of gel
or debris within the vitreous, which is the clear jelly-like substance
that fills the inside cavity of the eye. As these floaters move
about inside your eye, they are casting shadows onto the retina.
What causes
flashes and floaters?
The vitreous
is normally attached to the surface of the retina, which lines
the inside of your eye, like wallpaper. As we grow older and reach
middle age, the vitreous gel begins to breakdown into microscopic
clumps and strands. As the vitreous undergoes this degeneration,
it sometimes actually separates itself away from the retina. This
process is called posterior vitreous detachment, or PVD.
PVD can also occur in nearsighted people, people who have sustained
ocular trauma, or individuals who have recently undergone an ocular
procedure such as cataract surgery, or YAG capsulotomy. When floaters
appear suddenly, it can be quite alarming. Usually, when a PVD
occurs, you may suddenly see little dots, lines, cobwebs, or clouds
filling the vision of one of your eyes. Fortunately, the floaters
are usually harmless, and are a result of the normal aging process.
Flashes may also occur during a PVD as a result of the vitreous
tugging on the retina. The retina feels no pain, but if it is
stimulated, it will send a light signal to the brain. This often
can be observed as a shooting arc of light, or a burst of light
in the corner of your vision that is more easily observed at night
or when there is little surrounding outside light. Your eye will
continue to function normally with a PVD.
Are flashes
and floaters ever serious?
Occasionally,
the retina can be torn when a PVD occurs. This may cause a small
amount of bleeding, which can appear as new floaters. A retinal
tear can be serious if it develops into a retinal detachment.
Any sudden onset of new flashes or floaters should be promptly
evaluated by your eye doctor. Additionally, if you perceive
new symptoms after your evaluation, such as loss of part of your
peripheral vision, this requires a repeat examination.
Can anything
be done about floaters?
Floaters can
often interfere with normal vision and be bothersome while reading
or driving. Fortunately, floaters almost always diminish over
time and your brain will learn to ignore them, even if it takes
several months.
