Eye floaters are small shapes that drift across your vision, looking like specks, threads, or cobwebs. Most floaters are harmless age-related changes in the gel inside your eye. But a sudden burst of new floaters, especially with flashes of light, can signal a retinal tear or detachment and needs emergency care.
What Eye Floaters Actually Are
The inside of your eye is filled with a clear gel called the vitreous humor. Tiny clumps of collagen fibers within that gel cast shadows on your retina, the light-sensitive layer at the back of the eye. Those shadows are what you see as floaters.
You are likeliest to notice floaters when you look at a bright, plain background such as a blue sky, a white wall, or a computer screen. They appear to dart away when you try to look directly at them because they move with the fluid inside your eye.
Normal vs Concerning Floaters
| Feature | Usually Harmless | Possibly Serious |
|---|---|---|
| Onset | Gradual, over years | Sudden, over hours or days |
| Number | A few familiar shapes | Many new floaters at once |
| Flashes of light | None | Yes, especially in peripheral vision |
| Vision loss | None | Curtain, shadow, or blank area |
| Color | Gray or translucent | Red haze or shower of black specks |
| Action | Routine eye exam | Same-day ophthalmology evaluation |
Why Floaters Increase With Age
By age 50 to 70, the vitreous gel begins to liquefy and shrink. Eventually it pulls away from the retina, an event called posterior vitreous detachment (PVD). PVD is normal and very common. It often produces a sudden increase in floaters and brief flashes of light.
The trouble is that PVD can also tear the retina as it pulls. About 1 in 7 people with sudden new floaters from PVD will have a retinal tear, which can progress to retinal detachment and permanent vision loss without treatment. Any sudden change in floaters deserves an exam, ideally within 24 hours.
The Diabetes Connection: Diabetic Retinopathy
Sustained high blood sugar damages the small blood vessels of the retina. According to the National Eye Institute, diabetic retinopathy is the leading cause of blindness in working-age American adults.
Diabetic retinopathy progresses through stages:
- Mild non-proliferative retinopathy: tiny areas of swelling (microaneurysms) in retinal vessels.
- Moderate non-proliferative retinopathy: blockage of some vessels.
- Severe non-proliferative retinopathy: many blocked vessels deprive the retina of blood supply.
- Proliferative diabetic retinopathy (PDR): the retina grows fragile new blood vessels that bleed easily into the vitreous.
Vitreous Hemorrhage: The Floater Connection
When fragile new vessels bleed into the vitreous, the released blood produces a sudden shower of new floaters. People often describe a red haze, dark specks “like a swarm of gnats,” or a curtain of cobwebs. A larger bleed can drop vision to “hand motion only.”
This is not an everyday floater. It is a sign that retinopathy has progressed and needs urgent retinal evaluation. Treatment may include anti-VEGF injections (such as ranibizumab or aflibercept), laser photocoagulation, or vitrectomy surgery.
Other Conditions That Cause New Floaters
- Retinal tear: a break in the retina caused by vitreous traction.
- Retinal detachment: the retina lifts off the back of the eye, an emergency.
- Uveitis: inflammation inside the eye that releases inflammatory cells into the vitreous.
- Eye injury with bleeding into the vitreous.
- Migraine aura: zigzag lights and shimmering, usually lasting 20 to 60 minutes (different from true flashes).
Warning Signs of Retinal Detachment
Retinal detachment is painless but vision-threatening. The classic warning triad is:
- Flashes of light, especially at the edges of vision, often described as camera flashes or lightning streaks.
- Floaters appearing suddenly in large numbers.
- A shadow or curtain moving across part of your visual field.
If you have any of these, contact an ophthalmologist or visit the emergency room immediately. Retinal detachment treated within 24 to 72 hours has a much better outcome than detachment that persists for days.
How an Eye Doctor Evaluates New Floaters
Expect a dilated fundus exam, in which drops widen your pupils so the doctor can see the entire retina. They may also use:
- Slit-lamp biomicroscopy: high-magnification view of the front and back of the eye.
- Optical coherence tomography (OCT): cross-sectional imaging of the retina.
- B-scan ultrasound: used when blood obscures the view of the retina.
- Fluorescein angiography: dye photographs of retinal vessels to map leaks and blockages.
Eye Exam Schedule for People With Diabetes
The American Diabetes Association recommends:
- Type 1 diabetes: first dilated exam within 5 years of diagnosis, then yearly.
- Type 2 diabetes: dilated exam at diagnosis, then yearly.
- Pregnancy with pre-existing diabetes: exam before pregnancy or in the first trimester, then as advised.
- Anyone with retinopathy: more frequent follow-up as the ophthalmologist directs.
For more on diabetic vision changes, see our pages on vision changes and diabetes eye symptoms.
Treatment Options for Bothersome Floaters
Most floaters need no treatment. For floaters that significantly impair vision and quality of life, options include:
| Treatment | How It Works | Considerations |
|---|---|---|
| Observation | Brain adapts; debris settles | First-line for most people |
| YAG laser vitreolysis | Laser breaks large floaters into smaller fragments | Limited evidence; not widely offered |
| Vitrectomy | Surgical removal of the vitreous gel | Effective but carries risk of cataract, retinal tear, infection |
| Anti-VEGF injection | Reduces leakage from abnormal vessels | For diabetic retinopathy with vitreous hemorrhage |
| Panretinal photocoagulation | Laser reduces oxygen demand of peripheral retina | For proliferative diabetic retinopathy |
Reducing Your Risk
You cannot prevent age-related floaters, but you can reduce your risk of diabetes-related vitreous bleeding:
- Keep A1C in the target range agreed with your clinician.
- Control blood pressure (often a target under 130/80 mm Hg).
- Avoid smoking; smoking accelerates retinopathy.
- Have a yearly dilated exam even if your vision feels fine.
- Wear protective eyewear during sports and yard work to prevent injury.
The Bottom Line
Most eye floaters are a normal nuisance. The ones to take seriously are those that arrive suddenly, multiply quickly, come with flashes of light, or carry a shadow across your vision. If you have diabetes, these symptoms can mean a vitreous hemorrhage from retinopathy, and any of them in any person can mean retinal tear or detachment. When in doubt, call an ophthalmologist the same day. Eyes do not get a second chance.
