Sometimes, as we age or after
an injury to the eye, shadowy images may appear floating within the field of
vision.In other cases, these images
develop during the third trimester of gestation, as the fetal hyaloid artery,
running through the eyeball, regresses in late pregnancy. Blinking, eye drops or washes, or even a good
night’s sleep won’t make them go away. It’s these shadow-like images that are known as eye floaters.
The eye is filled with a liquid
substance (the vitreous humor), composed of 99% water and 1% solid matter that
includes collagen, calcium, and various other substances, that helps the eye
retain its shape and acts as padding against damage from injury.Floaters are not optical illusions; they are
accumulations of the solid matter within the vitreous humor that alter the way
the eye reflects light. By altering
light’s reflection, they become visible.
There is no specific form or
shape characteristic of eye floaters. Everyone who has them sees them
differently. Some people see rings while
others see spots, threads, or abstract fragments that resemble cobwebs. Some patients see just one floater while
others see several.
Due to the fluid nature of the
interior eye, it is impossible to look directly at one’s own eye floaters. They move in accord with deliberate eye
movements but settle into a gentle drift, usually toward the lower part of the
visual field, when the eye is still.
Once discovered, it seems
impossible to ignore eye floaters but, in most cases, no treatment is
necessary. Having floaters is a common
situation but it is almost always nothing to cause alarm. A survey of optometrists in the United
Kingdom (UK), conducted in 2002, indicated each British optometrist saw 14
patients every month that scheduled appointments because of eye floaters alone.
When medical intervention is
administered, eye floaters are removed in a surgical procedure called
vitrectomy. Unless there is risk of
further damage, most patients are advised to simply become accustomed to seeing
them, as surgical intervention brings with it the risk of complication that may
lead to a more serious condition. In
time, floaters actually become quite easy to overlook.
In rare cases, eye floaters are
the result of retinal detachment, which causes blood to leak into the vitreous
humor. In this situation, medical
attention is required immediately as blindness can result. Any time a person experiences the rapid onset
of random flashes across the field of vision or the sudden appearance of
multiple floaters, retinal detachment may have occurred, with or without an
accompanying injury, and an immediate ophthalmologic examination is critical.