Eye Floaters: Causes and When to Worry
Medically Reviewed by Dr. Pedro Yelamo Vera, MD
Licensed Physician No. 484814280 · Official Medical College of Bizkaia (Spain)Last reviewed: 5 November 2026
Eye floaters are usually harmless gel changes.
You don't have to figure this out alone
Dr. Pedro Yelamo Vera is an independent, bilingual GP licensed in Spain. Book a 15-minute video consultation in English or Spanish for €50, with a private electronic prescription issued under Spanish law when clinically appropriate.
Eye floaters are dots, threads or cobwebs that drift across your vision and move when your eye moves. Most are harmless and come from age changes in the gel inside the eye. They are urgent, the same day, if they appear suddenly, there are many at once, or they come with flashes of light or a shadow over part of your vision. This guide is by Dr. Pedro Yelamo Vera, a GP licensed in Spain (Colegiado No. 484814280).
- Floaters are small clumps in the vitreous, the clear gel that fills the eye.
- They are very common after 50 and in people who are short-sighted.
- You notice them most against a bright background, such as the sky or a white wall.
- A sudden shower of floaters, flashes or a curtain over your vision can mean a retinal tear or detachment.
- With those signs, get an eye check the same day. A video call cannot examine the retina.
What are eye floaters?
The inside of the eye is filled with a clear gel called the vitreous. With age, this gel becomes more liquid and forms small clumps or strands. These cast shadows on the retina, and we see them as dots, threads, rings or cobwebs that float. In Spain they are called moscas volantes, and doctors write miodesopsias.
They move when your eye moves and seem to dart away when you try to look at them. They show up best in bright light or against a pale background.
What causes floaters?
- Ageing of the vitreous gel, the most common cause.
- Short sight (myopia), which makes them start earlier.
- Posterior vitreous detachment (PVD): the gel pulls away from the retina. This is common after 50 and usually harmless.
- Cataract surgery or other eye surgery.
- Less often, swelling inside the eye (uveitis), bleeding into the gel, for example from diabetes, or a retinal tear.
Are eye floaters dangerous?
Floaters you have had for a long time that do not change are rarely a problem. The risk is in sudden changes. When the gel pulls away, it can tug on the retina and tear it. A retinal tear can lead to a detachment, which needs urgent treatment to save your sight. The NHS says these symptoms need a quick check because they could affect your vision for good.
What do flashes of light mean?
Flashes are streaks or sparks of light, often to one side, seen most in the dark. They happen when the gel pulls on the retina. Together with new floaters, they are a sign to have the retina checked that day.
Do not mix them up with a migraine aura. That is zigzag lines or bright lights that spread slowly, usually in both eyes, and go within an hour. Read more about migraine.
How are floaters checked?
An eye doctor (ophthalmologist) puts in drops to widen your pupil and looks at the back of the eye. This shows the gel and the whole retina. It is the only way to rule out a tear. So for new floaters with flashes, you need an exam in person. A video call is not enough.
Do floaters go away?
Many become less of a bother over time. They can sink lower in the eye, and the brain learns to ignore them, usually within a few months. No eye drops or tablets remove them. Only in rare cases, when they badly affect sight, an eye doctor may offer laser or surgery (vitrectomy). Both have their own risks.
What can I do in the meantime?
- Move your eyes up and down to shift a floater out of the centre of your vision.
- Wear sunglasses if bright light makes them stand out.
- Have regular eye checks if you are very short-sighted, have diabetes or have had eye surgery.
- Note when they started and if they change, to tell the eye doctor.
When is it urgent? Get seen the same day
Go the same day to an eye emergency service (urgencias de oftalmología) or a hospital A&E if:
- Floaters appear suddenly for the first time, or there are suddenly many more.
- You see flashes of light.
- A dark shadow or curtain covers part of your vision.
- Your sight goes blurry suddenly, or your eye hurts.
- They start after a blow to the eye or an operation.
When to call 112
Call 112 if you suddenly lose sight in one eye, or if sight problems come with weakness on one side of the body, a drooping face or slurred speech. This can be a stroke.
Frequently asked questions about eye floaters
Do eye floaters go away on their own?
Many become less noticeable over time, as they move and the brain gets used to them. Old floaters that do not change usually need no treatment.
Can stress or tiredness cause floaters?
They do not cause them, but you may notice them more. New floaters should be checked even if you think it is just tiredness.
Are floaters a sign of retinal detachment?
Rarely. But if they come on suddenly, with flashes or a shadow, it must be ruled out the same day.
What are eye floaters called in Spain?
Moscas volantes, or miodesopsias. Ask for urgencias de oftalmología if you need a same-day eye check.
Can a doctor assess floaters by video?
A video call can help judge how urgent it is, but only an exam in person can check the retina. For flashes, a curtain or new floaters, go to an eye emergency service.
Getting a medical assessment
If you have questions about eye symptoms that are not urgent, you can book a video consultation with Dr. Pedro Yelamo Vera, a physician registered in Spain, who can advise whether you need an eye check in person. You can also read about urgent, non-emergency video care, dry eye and a burst blood vessel in the eye. A prescription is never guaranteed: it is issued only where clinically appropriate after a genuine evaluation, as a private electronic prescription under Spanish law. This service is for urgent, non-emergency care. In an emergency, call 112.
This guide is general information. It does not replace the package leaflet or the advice of your doctor or pharmacist.
Sources
This content is written and reviewed by a licensed physician with reference to the following sources.
