What Causes Eye Floaters?

Eye floaters are generally caused by age-related changes inside the eyes. When you see floaters, you can see what appear like dark spots, lines, or webs drifting in front of your eyes. Eye floaters are often harmless and don't require treatment. In some cases, however, they can be caused by serious conditions, such as retinal detachment, and may require surgery. 

Anatomy

The retina is filled with a jelly substance called the vitreous, a hydrated extracellular matrix made primarily of water, collagen, and hyaluronan organized into a homogeneously transparent gel. Also called the vitreous humor, this jelly substance is crucial for vision since it helps the eye maintain its round shape and transmits light into the retina.

However, the vitreous doesn’t remain the same throughout life. When a person ages, the vitreous becomes more liquid, and small collagen fibers clump together, casting shadows on the retina and creating the floaters people see. This commonly begins to occur around age 50. 

Symptoms

Eye floaters are often harmless. If they don’t cause discomfort or are not accompanied by other symptoms, there is usually no need to worry.

However, they can signal a serious disease if they occur along with the following symptoms:

• The number of floaters increases suddenly
• Pain in the eye
• Flashes of light
• Peripheral vision loss
• Blurred vision

Causes

Eye floaters are often a normal part of aging.

Conditions that can cause floaters include:

• Vitreous detachment: The most common symptom of vitreous detachment is a sudden increase in the number of floaters. People who have this condition can also see flashes. A person's risk of vitreous detachment increases with age, and it is most common after age 80. The fibers of the vitreous can begin to pull away from the retina with age and may lead to detachment. In severe cases, it can lead to problems such as retinal detachment and a macular hole.
• Retinal detachment: A detachment can occur when the retina is pulled away from its normal position in the eye. A sudden increase in the number of eye floaters, flashes of light in one or both eyes, or a shadow over vision are symptoms of this condition
• Uveitis: Inflammation of the uvea, a structure located beneath the cornea of the eye, causes swelling and can destroy eye tissues. Uveitis causes reduced vision or can lead to severe vision loss. Early symptoms include floaters, eye pain, blurry vision, and sensitivity to light
• Vitreous hemorrhage: Bleeding in the vitreous can result from abnormal vessels that are prone to bleeding, normal vessels that rupture under stress, or extension of blood from an adjacent source. It is rare and occurs in seven cases per 100,000 population. This condition is related to diseases like diabetic retinopathy. Blunt or perforating trauma is the most common cause of vitreous hemorrhage in people under age 40
• Eye tumors: Tumors in the eye can be malignant or benign, and usually don't cause symptoms. Depending on the part of the eye it grows or its stage, eye tumors can cause floaters, visual field loss, blurry vision, or changes in the way the eye moves within the socket

Diagnosis

An eye care professional can diagnose the underlying condition causing eye floaters with an eye exam. The ophthalmologist or optometrist will dilate your pupil so they can see inside the eye. They may also check for signs of a retinal detachment or tear.

Treatment

Treatment for eye floaters depends on the cause. If eye floaters are not indicators of any other problem, they don't need to be treated. People often stop noticing them after a while and will usually learn to tolerate eye floaters when reassured that they aren't signaling an eye problem. When eye floaters impact vision or if there's a serious cause, surgery may be recommended. 

Vitrectomy is a surgical procedure that involves removing the vitreous from the eye and replacing it with a solution that mimics the vitreous. However, several risks are involved in this process—it can lead to a retinal tear or cataracts. There is also no guarantee the surgery will eliminate all floaters.

It is also possible to have laser surgery that will break up clumps of tissue that are causing the floaters. Some people who have this treatment report improved vision; others notice little or no difference. There is a risk that the laser can potentially damage the retina.

A Word From Verywell

Eye floaters can be a normal part of aging and are not a cause for concern in most cases. Getting your eyes checked by an eye doctor is the best way to make sure that your vision is healthy. Whether you are experiencing floaters or not, it is essential that you schedule an appointment with an eye care specialist every two years—or more frequently if you have a family history of glaucoma or if recommended by your healthcare provider. Routine eye exams can help catch and treat any serious conditions that cause eye floaters before the condition progresses.