Those squiggly lines drifting across your vision are called floaters, and they’re caused by tiny clumps of collagen fibers floating inside the gel-like fluid that fills your eyeball. When light enters your eye, these clumps cast shadows on the retina (the light-sensitive layer at the back of your eye), and your brain picks up those shadows as grey shapes. Most floaters are completely harmless, though a sudden increase can signal something more serious.
What’s Actually Happening Inside Your Eye
About two-thirds of your eyeball is filled with a clear, gel-like substance called the vitreous. It’s roughly 99% water, with the remaining fraction made up of collagen fibers and hyaluronic acid that give it structure. Over time, those collagen fibers can break loose, drift together, and form small clumps or strands. These clumps are too small to see directly, but because they sit between the lens of your eye and your retina, they intercept incoming light and throw tiny shadows onto the retina’s surface.
That’s why floaters seem to move when you try to look at them. They’re suspended in fluid, so every time your eye shifts, the liquid sloshes slightly and carries the fibers along with it. People describe them as squiggly lines, cobwebs, threads, dots, or even shapes that look like bugs or hairs. They’re most noticeable when you’re looking at a bright, uniform background like a white wall or a blue sky, because the contrast makes those shadows easier to detect.
Why They Get Worse With Age
Floaters can appear at any age, but they become far more common after your mid-40s because the vitreous gel gradually breaks down. By age 50, about a quarter of the vitreous has shifted from its original gel consistency to a more watery state. By 80, that figure climbs to 62%. As the gel liquefies, collagen fibers that were once evenly distributed lose their support structure and collapse into visible clumps.
Eventually, the shrinking vitreous can pull away from the retina entirely, a process called posterior vitreous detachment (PVD). This is extremely common: roughly 24% of people in their 50s have it, and 87% of people in their 80s. When PVD happens, the newly separated vitreous folds and wrinkles, creating larger shadows and often a noticeable burst of new floaters. For most people, PVD is harmless and the floaters gradually become less bothersome as they settle lower in the eye or the brain learns to tune them out.
Nearsightedness speeds this process up. People with significant myopia tend to have longer eyeballs, which stretches the vitreous and accelerates its breakdown.
When Floaters Signal a Problem
A few floaters that have been around for weeks or months are almost always benign. The situation changes when symptoms appear suddenly and dramatically. Among patients who show up with a sudden onset of new floaters, about 14% turn out to have a retinal tear, which can lead to retinal detachment if untreated.
The warning signs that need prompt attention are:
- A sudden flood of new floaters, especially if they appeared within hours or days rather than gradually over time
- Flashes of light in one or both eyes, often described as brief lightning streaks or camera flashes in your peripheral vision
- A dark shadow or curtain creeping across part of your visual field from any direction
Any of these warrants a same-day eye exam. Retinal detachment is painless, so vision changes are the only clue. Caught early, a small tear can be sealed with a quick laser procedure. Left untreated, a full detachment can cause permanent vision loss.
How an Eye Doctor Evaluates Floaters
If you go in for new or worsening floaters, the key test is a dilated eye exam. Your eye doctor will use drops to widen your pupils, which gives them a clear view of the vitreous and the entire retina, including the far edges where tears are most likely to develop. The dilation itself takes about 20 to 30 minutes to kick in, and your vision will be blurry and light-sensitive for a few hours afterward, so bringing sunglasses and having someone else drive is a good idea.
If the exam shows no tears or detachment, the floaters are considered benign, and no treatment is typically needed. Your doctor may recommend a follow-up exam in a few weeks to confirm nothing has changed.
Treatment Options for Persistent Floaters
Most floaters fade on their own over months as they drift out of your central line of sight or as your brain adapts to them. For the majority of people, no treatment is necessary.
When floaters are dense enough to genuinely interfere with daily life, two procedures exist. One uses a laser to break up large clumps of collagen into smaller, less noticeable pieces. The other is a surgical procedure that removes the vitreous gel entirely and replaces it with a saline solution. Both carry risks, including cataracts and, rarely, retinal detachment from the procedure itself. Notably, no randomized controlled trials have directly compared these two approaches, so the evidence base for choosing between them remains limited. Most ophthalmologists reserve both options for severe cases where floaters significantly impair vision or quality of life.
No supplements, eye drops, or dietary changes have been proven in rigorous clinical trials to reduce or eliminate existing floaters.
Other Things You Might Be Seeing
Not every moving speck in your vision is a floater. If you notice tiny bright dots darting rapidly along fixed paths when you look at a clear blue sky, you’re likely seeing white blood cells traveling through the small capillaries on your retina’s surface. This is called the blue field entoptic phenomenon, and it’s completely normal. The key difference: these bright dots follow consistent paths and move quickly, while floaters drift lazily and change direction when your eyes move.
Visual migraines can also produce shimmering, zigzag lines, but these typically expand across your visual field over 20 to 30 minutes and then disappear, often followed by a headache. Floaters, by contrast, persist and move with your gaze rather than spreading in a fixed pattern.