Floaters are a common sight for many people. The term is a catchall for the specks, threads, or cobweb-like structures in your vision. The floater is a tiny cluster of cells or fleck of protein. It is suspended in the clear gel behind the pupil, this looks a little like raw egg white. It supports and fills the inner two thirds of the eyeball. The vitreous provides structure and support for the eye which is particularly important when the eye is growing. It allows light to pass straight through it, to reach the retina. The vitreous connects to the retina in places and is as quite firmly attached around the optic nerve.
As we age the vitreous slowly shrinks becoming a bit stringy as it breaks up. These strands can cast shadows on the retina, causing us to notice the floater. The shrinking vitreous can tug on the retina and pull away from it. This event, called a posterior vitreous detachment, is common, and usually doesn’t threaten vision.
Who can get floaters?
Floaters appear more commonly in people who are myopic (short sighted), who have had cataract surgery or a previous eye injury, as well as people with diabetes. Most people tolerate floaters but some do find that floaters are a nuisance and negatively affect their vision or disrupt their ability to read.
Floaters move as your eyes move. They appear to zoom away when you try to look directly at them, and typically drift slowly back when your eyes stop moving.
Flashes are sparks, strands, or arcs of light that flicker across your visual field. These occur when the vitreous gel bumps, rubs, or tugs against the retina. Like floaters, flashes are generally harmless and require no treatment. Although they can be a warning sign of trouble particularly when they appear suddenly or become more plentiful.
Sometimes floaters and flashes signal a condition that can lead to vision loss. In about one in six people, traction from the posterior vitreous detachment causes the retina to tear. Fluid from inside the eye can then seep through the tear and separate the retina from the tissues that nourish it. This separation, called retinal detachment, can lead to permanent vision loss.
Retinal tears and detachments are painless.
Key warning signs include:
- New onset of floaters and flashes.
- A sudden change in what an old floater looks like, or lots of new ones.
- Gradual shading or dimming of vision from one side (like a curtain being drawn across).
- Rapid decline in sharp, central vision.
- Wrinkles or wobbles in your vision.
Because there is little difference between what benign floaters look like, compared to those which are signs of something more serious, it is important to have your eye checked. It is prudent to assume the worst and to get this done as soon as possible. A dilated fundus examination, where drops which dilate your pupils are used, is the only way to properly examine the back of the eye and retina.
If your floaters aren’t a sign of retinal damage above, they often disappear completely or become less noticeable. Sometimes ophthalmologists perform surgery or laser treatment for benign floaters when they are very disruptive to vision. But for most people the risk to vision of the surgery is greater than the problem posed by the floater. If floaters become a nuisance, moving your eyes up and down, or left and right can shift the floater and provide temporary relief.