Eye floaters are small, shadowy shapes that drift across a person’s field of vision. They may appear as spots, threads, squiggly lines, cobwebs, or bubbles, and move when the eyes move. Also called vitreous opacities, floaters are most noticeable when looking at bright, plain backgrounds, such as a blue sky or a white wall.

Although floaters can occur at any age, they become more common as people get older. Most people experience them at some point as they age. While exact numbers for the United States are not specified, research suggests that up to three-quarters of people report seeing floaters at some point in their lives.

Most floaters are harmless and do not require treatment. However, if they become bothersome or are linked to another eye condition, treatment options are available.

Eye floaters are visual disturbances that look like small, drifting shapes in a person’s field of vision. Although they can look like dust or debris on the surface of the eye, floaters are caused by tiny clumps or strands within the clear, gel-like vitreous fluid that fills the eye. When light passes through the eye, these clumps cast shadows on the retina, which is the light-sensitive tissue responsible for sending visual signals to the brain.

In a healthy eye, the vitreous is a clear gel that helps the eye keep its shape and allows light to reach the retina without obstruction. Over time, collagen fibers within the vitreous may clump together, creating shadows that appear as floaters. Floaters move as the eyes move and may drift away when you try to look at them directly. They are most noticeable against bright, uniform backgrounds.

Floaters can be categorized based on their origin:

• Primary floaters: These develop from changes within the vitreous itself, such as clumping of collagen fibers within the gel.
• Secondary floaters: These result from other processes, such as bleeding into the vitreous, inflammation, or the growth of other cells in the eye.

For some people, floaters are a minor annoyance. For others, floaters can become large or numerous enough to interfere with vision and quality of life. In certain cases, floaters may be accompanied by other symptoms, such as flashes of light or a dark curtain in the vision, which can signal a serious eye condition.

The most common cause of eye floaters is the natural aging process. As people age, collagen fibers within the vitreous gel can clump together. These clumps cast shadows on the retina, which appear as floaters.

Other causes of floaters include:

• Posterior vitreous detachment: This occurs when the vitreous pulls away from the retina, often resulting in a sudden increase in floaters.
• Retinal tears or retinal detachment: If the shrinking vitreous tugs on the retina, it can cause the retina to tear or pull away from the back of the eye. This requires immediate medical attention.
• Bleeding into the vitreous: Conditions such diabetes, trauma, or blocked blood vessels in the retina can cause bleeding in the eye, which leads to floaters.
• Eye inflammation (uveitis): Inflammation in the eye or elsewhere in the body, can cause floaters along with blurry vision, eye pain, and sensitivity to light. If you experience these symptoms, seek medical care promptly.
• Rarely, floaters may be caused by other materials or cells in the vitreous, such as after eye surgery or injections.

Risk factors for eye floaters include:

• Older age
• Nearsightedness (myopia)
• Diabetes
• Previous cataract surgery or other eye surgery
• Eye injury or trauma
• Inflammatory diseases of the eye
• Certain genetic conditions such as Marfan syndrome or Stickler syndrome

Symptoms of eye floaters may include:

• Small, shadowy shapes drifting across the field of vision
• Spots, specks, dots, or bubbles in the field of vision
• Threads, squiggly lines, or cobweb-like shapes
• Shapes that move as the eyes move and seem to drift away when looked at directly

The following are not symptoms of floaters but associated with more serious conditions (such as retinal tear or detachment) that can also lead to floaters. People should seek immediate medical attention if any of the following occur:

• Flashes of light, often at the edge of a person’s vision
• A sudden increase in the number of floaters
• A dark shadow or curtain blocking part of a person’s vision

To diagnose eye floaters, your doctor will review your medical history, conduct a dilated eye exam, and may order one or more diagnostic tests. Floaters are usually evaluated by an ophthalmologist or optometrist.

Your doctor may ask about your symptoms, such as the appearance and number of floaters, whether you have noticed flashes of light, and if you have any risk factors like nearsightedness, diabetes, or a history of eye surgery or injury. During the eye exam, your doctor will examine your eyes to look for floaters and check for signs of more serious eye conditions, such as retinal tears or detachment.

Additional tests that may be used to make a diagnosis include:

• Dilated eye exam: The doctor will administer eye drops to widen your pupils and allow examination of the vitreous and retina. This is the main test for diagnosing floaters and related eye conditions.
• Slit lamp exam: The doctor uses a special microscope to examine the structures at the front and back of your eye, helping to identify floaters and rule out other issues.
• Indirect ophthalmoscopy with scleral depression: In this test, the doctor checks for retinal tears or breaks by gently pressing on the outside of the eye while examining the retina with an indirect ophthalmoscope. In this test, the doctor wears an instrument on their head that shines a light into the eye and holds a lens close to the eye This test helps your eye doctor visualize the often difficult to visualize peripheral retina.
• Ocular ultrasonography: If the view of the retina is blocked or unclear by other means, an ultrasound can help detect floaters, posterior vitreous detachment, or retinal detachment.
• Optical coherence tomography (OCT): This imaging test may be used to evaluate a posterior vitreous detachment.

These tests help your doctor determine the extent of your floaters or detect a more serious eye problem.

Most cases of eye floaters do not require any treatment unless they significantly affect vision or quality of life. In such cases, several treatment options are available to help manage symptoms, including:

• Observation: Over time, many people adapt to floaters or notice them less as they settle below the line of sight.
• Treating underlying conditions: If floaters are caused by another eye problem, such as infection, inflammation, or bleeding, treating that condition may help the floaters resolve.
• Pars plana vitrectomy: This surgical procedure removes the vitreous gel. It is the most definitive treatment for floaters, but carries risks such as infection, cataract formation, and retinal detachment. It is usually reserved for people with severe, persistent symptoms that interfere with daily life.
• Nd:YAG laser vitreolysis: This less invasive procedure uses a laser to break up floaters, making them less noticeable. The effectiveness of this treatment varies. Potential risks include retinal holes, bleeding, increased eye pressure, and damage to surrounding structures.

People with eye floaters may be at increased risk for certain complications or associated conditions, including:

• Retinal tear: A break or hole in the retina, which can lead to vision loss if not treated promptly.
• Retinal detachment: When the retina pulls away from the back of the eye, causing a sudden loss of vision and requiring emergency treatment.
• Vitreous hemorrhage: Bleeding into the vitreous gel, which can cause a sudden increase in floaters and blurry vision.
• Macular hole: A small break in the macula, the part of the retina responsible for sharp, central vision.
• Permanent vision loss: In rare cases, floaters are associated with retinal detachment or severe infection, which can result in permanent loss of vision if not treated promptly.

The following complications may occur after surgical procedures to treat floaters:

• Cystoid macular edema: Swelling in the central part of the retina (macula), which can affect central vision.
• Increased intraocular pressure or glaucoma: A rise in pressure inside the eye, which can damage the optic nerve and lead to vision loss.
• Infection (endophthalmitis): A rare but serious infection inside the eye, most often associated with surgical treatment.
• Cataract formation: Clouding of the eye’s lens, which can develop after certain treatments such as vitrectomy.

The outlook for people with eye floaters varies depending on factors such as the underlying cause, the number and size of floaters, and the presence of any associated eye conditions. For most people, floaters are harmless and do not interfere significantly with vision or daily activities.

However, in some cases, floaters can be persistent, numerous, or bothersome enough to affect quality of life. Rarely, floaters may be a sign of a more serious eye problem, such as a retinal tear or detachment, which can lead to permanent vision loss if not treated promptly. To increase your chances of a good outcome, see your eye doctor if you experience changes in your vision.

“The Yale Eye Center has an experienced team of ophthalmologists and optometrists ready to provide a comprehensive evaluation of your floaters to rule out any vision threatening pathology and to determine the best course of treatment,” says Mercy Kibe, MD, a vitreoretinal surgeon at the Yale Eye Center.