Floaters and Flashes
Drifting spots and brief light sparks in your vision
Quick Facts
- Type: Eye/vision symptom complex
- Common cause: Age-related shrinking of the vitreous gel
- Usually: Harmless, but can signal retinal problems
- Warning: Sudden many new floaters or flashes need urgent care
Overview
Floaters are small shapes, such as dots, threads, squiggles, or cobwebs, that drift across your field of vision and seem to move when you try to look at them. Flashes are brief sparkles, streaks, or arcs of light that appear, often at the edge of vision. Both are very common and are usually caused by normal age-related changes inside the eye.
The inside of the eye is filled with a clear gel called the vitreous. As people age, this gel shrinks and pulls away from the retina, casting shadows that are seen as floaters and tugging on the retina to produce flashes. While most floaters and flashes are harmless, a sudden increase, especially with a shower of new floaters, many flashes, or a shadow in your vision, can be a sign of a retinal tear or detachment, which is an emergency that needs immediate care.
Symptoms
Floaters and flashes are themselves visual symptoms. People typically describe:
- Floaters: moving specks, dots, lines, cobwebs, or ring shapes, most noticeable against a bright, plain background like a clear sky or white wall
- Flashes: brief sparks, streaks, or arcs of light, often to the side and more noticeable in dim light
- Floaters that drift when the eyes move and seem to dart away when looked at directly
Warning signs that require urgent eye care include: a sudden burst of many new floaters, frequent or persistent flashes, or a dark curtain or shadow spreading across part of your vision. These can indicate a retinal tear or detachment.
Common Causes
Most floaters and flashes come from changes in the vitreous gel, but other conditions can cause them. Causes include:
- Posterior vitreous detachment: the most common cause, in which the gel shrinks and separates from the retina with age, producing new floaters and flashes.
- Retinal tear or detachment: the gel pulls hard enough to tear the retina; this is an emergency.
- Bleeding inside the eye: from diabetes or injury, which appears as many floaters.
- Inflammation inside the eye (uveitis): which can release cells seen as floaters.
- Migraine: can cause flashing or shimmering light, usually in both eyes and lasting minutes.
Associated Symptoms
Depending on the cause, floaters and flashes may occur with other symptoms that help point to the problem:
- A shadow, curtain, or loss of side vision, suggesting retinal detachment
- Blurred or reduced vision
- Eye redness or pain, which can suggest inflammation
- Headache or shimmering zigzag patterns in both eyes, suggesting migraine
- A sudden large increase in floaters in someone with diabetes, suggesting bleeding
Noticing these companion symptoms helps determine how urgently you need to be seen.
Diagnosis & Evaluation
An eye doctor can usually find the cause of floaters and flashes with a thorough eye examination. This includes:
- Dilated eye examination: drops widen the pupil so the doctor can carefully inspect the retina and vitreous, especially the edges where tears often occur.
- Examination of both eyes: to check for tears, detachment, bleeding, or inflammation.
- Optical coherence tomography (OCT) or ultrasound: imaging used when the view is unclear or bleeding is present.
Anyone with new or sudden floaters and flashes should have a prompt dilated examination to rule out a retinal tear or detachment.
Treatment & Management
Treatment depends on the cause. Most ordinary floaters need no treatment, while retinal emergencies require prompt intervention.
- Reassurance and monitoring: for harmless, age-related floaters, which often become less noticeable over time as the brain adapts.
- Laser or freezing treatment: to seal a retinal tear before it progresses to detachment.
- Surgery: to repair a detached retina, an urgent procedure to preserve vision.
- Treating the underlying condition: such as controlling diabetes, treating inflammation, or addressing bleeding.
- Vitrectomy: rarely, surgery to remove the vitreous gel may be considered for severe, persistent floaters.
Acting quickly on warning signs greatly improves the chance of saving vision when a retinal problem is present.
When to See a Doctor
A few longstanding, stable floaters are usually harmless. However, seek urgent, same-day eye care if you notice any of the following, which can signal a retinal tear or detachment:
- A sudden shower or large increase in new floaters
- New or frequent flashes of light
- A dark curtain, shadow, or veil spreading across your vision
- A sudden loss of side or central vision
If you cannot reach an eye doctor quickly, go to an emergency department. Prompt treatment of a retinal tear can prevent permanent vision loss.
Frequently Asked Questions
Are eye floaters and flashes dangerous?
Most are caused by harmless age-related changes in the eye's gel and are not dangerous. However, a sudden increase in floaters, new flashes, or a shadow across your vision can signal a retinal tear or detachment, which is an emergency requiring same-day eye care.
Why do I see flashes of light?
Flashes often happen when the vitreous gel tugs on the retina as it shrinks with age. They can also be caused by a retinal tear. Flashes from migraine are different, usually appearing as shimmering zigzags in both eyes and lasting several minutes.
Do floaters go away on their own?
Harmless floaters often become less noticeable over weeks to months as they settle and the brain learns to ignore them, though they may not disappear completely. Floaters from bleeding or inflammation improve when the underlying cause is treated.
When should I worry about floaters and flashes?
Seek urgent eye care if you suddenly notice many new floaters, frequent flashes, or a curtain or shadow moving across your vision. These can mean a retinal tear or detachment, where fast treatment can prevent permanent vision loss.
Can floaters be treated?
Most floaters need no treatment. For bothersome, persistent floaters, laser treatment or surgery (vitrectomy) may rarely be considered. When floaters are caused by a retinal tear, bleeding, or inflammation, treating that underlying problem is the priority.
References
- American Academy of Ophthalmology. Floaters and Flashes.
- National Eye Institute (NEI). Floaters.
- MedlinePlus, U.S. National Library of Medicine. Floaters.
- Mayo Clinic. Eye floaters — Symptoms and causes.