What Causes Eye Floaters?
Most are harmless but sudden increase requires quick care
Most are harmless but sudden increase requires quick care
Eye floaters are small, shadowy shapes or squiggly whitish lines that sometimes drift into your field of vision, often when you blink or look into bright light. You can’t feel them or touch them, and they seem to dart away when you try to focus on them. Should you be concerned?
In most cases, no. Eye floaters are generally harmless. However, if you suddenly see more of them, especially if you also have flashes of light or loss of vision, they might be a sign of an underlying condition that requires medical attention. Being aware of the causes and symptoms associated with floaters can help you determine when to call an eye doctor.
Where do eye floaters come from?
Eye floaters develop due to changes in the vitreous humor, which is the gel-like substance that fills the space between the lens and the layer of tissue at the back of the eye called the retina. Various factors contribute to the formation of eye floaters, including:
1. Age
The most common cause of eye floaters is aging. As we age, the eye’s vitreous humor starts to shrink and liquefy, leading to the formation of tiny clumps of collagen fibers. These clumps cast shadows on the retina, which we perceive as floaters. Eventually as we age, the vitreous gel can separate from the retina causing a posterior vitreous detachment (PVD).
PVD itself is usually harmless, but if it pulls on the retina, it can cause a retinal tear or retinal detachment.
2. Eye infections and inflammation
Inflammation inside the eye, particularly in the middle layer of the eye known as the uvea, is called uveitis. It can occur due to infections, autoimmune diseases or other underlying health issues and cause floaters.
3. Eye trauma or injury
Trauma to the eye, such as being hit in or near the eye socket, can lead to vitreous detachment or bleeding within the eye. Both can cause floaters.
“Any time you have an eye injury, you should be evaluated by an eye doctor to rule out serious complications that may threaten your vision, like retinal tear or detachment,” says Quang Nguyen, MD, an ophthalmologist at Scripps Clinic Torrey Pines and Scripps Clinic Encinitas.
4. Retinal tears and detachments
A retinal tear occurs when the vitreous humor pulls too hard on the retina, creating a small break. Without treatment, this can progress to retinal detachment, a serious condition that happens when the retina separates from the blood vessels that provide oxygen and nutrients to the eye.
Symptoms of retinal detachment include a sudden increase in floaters, flashes of light or a reduced field of vision, especially peripheral side vision. Retinal detachment is a medical emergency that can lead to vision loss and requires immediate medical attention.
5. Diabetic retinopathy
“People with diabetes are at risk of developing diabetic retinopathy, a condition where high blood sugar levels damage the blood vessels in the retina,” explains Dr. Nguyen. “As the disease progresses, abnormal blood vessels can grow and leak into the vitreous, leading to floaters and vision problems.”
6. Hemorrhages (bleeding in the eye)
In addition to diabetic retinopathy, causes of bleeding into the vitreous include high blood pressure and retinal tears. Blood cells floating in the vitreous can appear as eye floaters. Depending on the cause, treatment may be needed to clear the blood and restore vision.
7. Eye surgeries and medications
Certain eye surgeries, such as cataract removal, can lead to vitreous changes and increase the likelihood of floaters. Additionally, some medications injected directly into the eye to treat various conditions can cause temporary or permanent floaters.
When should you see an eye doctor?
“While occasional floaters are usually harmless, you should see an eye doctor immediately if you experience a sudden increase in floaters, flashes of light, eye pain or vision loss,” says Dr. Nguyen. “These could indicate a serious problem, such as a retinal tear, detachment or other condition that requires urgent treatment.”