“Floaters” in your field of vision
Normal versus Abnormal
Do you see semi-transparent specs of stuff floating across your field of vision? They seem to be right inside your eyes so should you be worried?
About eight out of every 10 adults see these specs and although they describe them in different ways, most of us call them floaters.
In the vast majority of cases, they are no cause for concern and result from normal aging. For some individuals, however, floaters, especially when accompanied by brief flashes of light, can be signs of an underlying eye problem that needs medical attention.
In order to understand floaters, it is important to know exactly how your eye works.
Light enters through the cornea, the front window of the eye, and is focused by the lens onto the retina at the back of the eyeball. The retina is made up of specialized cells that convert light into electrical signals which are carried by the optic nerve to the brain for processing.
The retina functions like film in an old- fashioned camera before the days of digital photography. And the brain performs the role of a film processing lab, converting the retina’s signals into images.
The interior of the eyeball is filled with a colourless, transparent jelly-like substance called vitreous. When you are young, vitreous is fairly thick and has the consistency of Jell-O. As you age, it begins to liquefy, with some fluid pockets forming within the eyes.
Furthermore, some bits of the vitreous will clump together, and this is what causes floaters. When the tiny clumps pass in front of light streaming into the eye they cast shadows on the retina, creating ghostly images of semi-transparent dots, lines and squiggles.
Floaters usually become more apparent when you are looking at a bright background such as the daytime sky. They even seem to dart about as they swish around in the partly liquefied vitreous gel.
Overtime, the vitreous may condense further and can start to separate from the retina. That’s when you can run into trouble. The sticky vitreous tends to pull on the retina and may create a tear or hole in the light-sensitive cells.
Your retina is like wallpaper and this sticky gel starts to tug on it and this creates tears in weak spots. The liquefied gel can then seep into the hole causing the retina to separate from the supportive tissue at the back of the eye. It’s like bubbles forming under your wallpaper.
This condition is known as retinal detachment and it could lead to permanent vision loss if not treated immediately.
Fortunately it can be fixed. But getting timely medical treatment is critical. That means you need to recognize the warning signs.
A sudden cascade of new floaters, plus the presence of quick flashes of light at the edge of your vision are two red flags that something might be seriously wrong. In particular, the flashes may indicate that the vitreous is tugging on the retina. Ideally you should be seen by a physician in 24 to 48 hours.
If the floaters and flashes are followed by what appears to be a dark curtain or shade being pulled across your vision, then head to the nearest hospital emergency department. The “curtain” likely means there is a tear and liquid vitreous is spilling behind the retina.
Surgeons can use several different techniques to patch the tear and press the retina into its proper place—firmly affixing it to the back wall of the eye. For instance, they may use a laser beam, an injection of specialized gases or a silicon band that temporarily wraps around the eye.
Although a retinal detachment can happen to anyone, some people are at greater risk of developing this condition, including those who are nearsighted, have had a previous eye injury or have undergone eye surgery such as cataract removal.
Diabetics are also prone to bleeds in the eye although the underlying cause is their diabetic neuropathy, a common symptom of Type 2 diabetics.
The good news is that a retinal detachment can usually be repaired and most people are left with only minor distortions in their overall vision.