What is happening
The inside of the eye is filled with a clear gel called the vitreous. Over a lifetime that gel gradually liquefies and shrinks, and at some point it peels away from the surface of the retina. This is called a posterior vitreous detachment, or PVD. It is a normal age-related event, not a disease, and most people will experience it — commonly in their fifties, sixties, or seventies, and earlier in people who are nearsighted or who have had cataract surgery or an eye injury.
As the gel separates, small condensations of collagen inside it cast shadows on the retina. Those shadows are what you see as floaters. Where the gel is still stuck to the retina, the tug on the retinal tissue is interpreted by the brain as a flash of light.
Symptoms
- New specks, dots, cobwebs, or strands that drift across your vision and move when your eye moves
- A larger ring or crescent-shaped floater, often described as a hair, a fly, or a smudge on a lens
- Brief arcs or streaks of light, usually off to the side, most noticeable in a dark room or when moving the eye quickly
Floaters are most obvious against a plain bright background — a white wall, a page, a clear sky.
Why we want to see you promptly
In most people the vitreous separates cleanly and nothing further happens. But in roughly one in ten patients with a new symptomatic PVD, the gel is adherent enough in one spot to tear the retina as it pulls away. A retinal tear that is found early can be sealed in the office with laser in a matter of minutes. A tear that goes unrecognized can allow fluid under the retina and progress to a retinal detachment, which requires surgery.
There is no way to tell from the symptoms alone which patients have a tear. Anyone with new floaters or flashes should have a dilated examination, ideally within a few days.
What the exam involves
We dilate both eyes and examine the retina all the way to its far edge, where tears most often occur. This usually includes scleral depression — gentle pressure on the outside of the eyelid or eye with a small smooth instrument to bring the extreme periphery into view. It is briefly uncomfortable but not painful. We may also take wide-field photographs, an OCT scan, or, if a hemorrhage blocks the view, an ultrasound.
What to expect afterward
If no tear is found, no treatment is needed. The floaters themselves are harmless. Over weeks to months they typically settle below the line of sight and the brain learns to ignore them, so most people become far less aware of them even though the floaters have not physically gone away. Persistent, visually disabling floaters can occasionally be removed with vitrectomy, but this is reserved for carefully selected patients after the situation has been stable for many months.
Because a tear can appear in the first several weeks after the gel separates, we usually ask you to return for a repeat dilated examination, and to come back sooner if your symptoms change.
When to call us right away
Call us at (315) 445-8166 without waiting for your scheduled visit if you notice:
- A sudden shower of many new floaters, or a burst of black specks
- Flashing lights that are increasing rather than settling
- A dark curtain, shadow, or veil coming in from any edge of your vision
- A drop in your central vision
These can be signs of a retinal tear or detachment, and they should be evaluated the same day.