New Floaters or Flashes
Symptoms, Causes & Treatment
Understanding floaters and flashes: when new floaters are a medical emergency, what posterior vitreous detachment means, and how retinal tears are treated.
What Are Floaters and Flashes?
Floaters are spots, threads, or webs that drift across your visual field, caused by clumps within the vitreous gel. Flashes are brief sparks or arcs of light caused by traction on the retina. Both can indicate posterior vitreous detachment (PVD) — a normal ageing change — or, in 10–15% of cases, a retinal tear requiring urgent laser treatment.
While most new floaters are benign, the risk of retinal tear means that all new floaters with flashes of light require same-day urgent ophthalmology assessment. Retinal detachment, if untreated, causes permanent vision loss.
All new floaters with flashes of light require same-day urgent eye assessment. Do not wait to see if they settle — attend an eye emergency clinic or A&E.
What Do Floaters and Flashes Look Like?
Distinguishing benign PVD floaters from floaters signalling retinal tear depends on character, onset, and associated symptoms.
New or increased number of floaters (spots, strings, shadows in vision) · Flashes of light (photopsia) · Usually more noticeable on bright backgrounds or blue sky · Typically worsen in dark environments
Sudden shower of new floaters with flashes — possible vitreous haemorrhage or retinal tear, attend A&E immediately · Dark curtain or shadow across part of visual field (retinal detachment — 999) · Central grey patch or distortion (macular disease)
A sudden shower of many new floaters, floaters with flashing lights, or any shadow or curtain across part of your visual field is a retinal detachment emergency. Attend A&E immediately — retinal detachment requires surgical repair within hours to preserve vision.
What Causes Floaters and Flashes?
Most new floaters are caused by posterior vitreous detachment (PVD), a normal age-related process. However, a significant minority signal retinal tear or detachment requiring emergency treatment.
Posterior vitreous detachment (PVD) occurs when the vitreous gel separates from the retina. This causes floaters and flashes. In most cases it is benign, but it can cause retinal tears in 10–15% of cases requiring urgent assessment.
Cataracts cause gradual clouding of the lens, producing progressive blurring, glare, and halos. Cataract extraction is the most commonly performed surgical procedure in the UK and is highly effective.
Age-related macular degeneration (AMD) affects central vision. Wet AMD causes rapid central vision loss from neovascularisation and requires emergency anti-VEGF injection. Dry AMD progresses slowly.
Acute angle-closure glaucoma causes sudden severe eye pain, nausea, red eye, and halos around lights. It is caused by sudden blockage of aqueous drainage. This is an ocular emergency requiring immediate ophthalmology treatment.
Uveitis is inflammation of the uveal tract (iris, ciliary body, choroid). It presents with eye pain, photophobia, and circumcorneal injection. It is associated with HLA-B27 conditions including ankylosing spondylitis.
Dry eye disease affects 5–15% of adults and occurs when tears evaporate too quickly (evaporative dry eye from meibomian gland dysfunction) or are produced in insufficient quantity (aqueous deficiency). Both cause ocular surface damage.
Key Risk Factors
How Are Floaters Investigated?
All new floaters with flashes require urgent dilated fundal examination to assess for retinal tear or detachment. OCT imaging and fundoscopy are performed by an ophthalmologist. Any visual field defect confirms retinal detachment.
How Are Floaters and Retinal Tears Treated?
Retinal tears are treated with laser photocoagulation (retinopexy) or cryotherapy under local anaesthetic as a day procedure. Retinal detachment requires surgical repair (pneumatic retinopexy, scleral buckle, or vitrectomy). Benign PVD requires no treatment.
Supportive Measures
There is no self-management for new floaters and flashes. Attend an eye emergency clinic or A&E urgently. After PVD is confirmed with no retinal tear, most people adapt to stable floaters over weeks. Avoid contact sports and straining in the weeks after PVD diagnosis.
After PVD: Monitoring and Follow-Up
After PVD, a 4–6 week follow-up examination is standard to confirm no delayed retinal tear. If symptoms change (new floaters, flashes, or field loss), re-attend immediately. Highly myopic individuals should have regular dilated fundal examinations throughout life.
When Should You Seek Medical Advice for Floaters?
Sudden shower of new floaters with flashing lights · Curtain or shadow across part of your vision · Vision suddenly going dark in one area. These indicate possible retinal detachment — attend A&E immediately.
You have developed new floaters in the last 24–48 hours · Your floaters are accompanied by flashes of light · You have high myopia and developed new floaters · You have noticed any change in your peripheral vision.
How Can You Reduce Your Risk of Retinal Problems?
Retinal detachment cannot always be prevented, but these measures reduce risk and support early detection.
Attend regular NHS sight tests (free every 2 years on the NHS, more frequently if you are diabetic, over 60, or have glaucoma in the family). Eye tests detect glaucoma, retinal disease, and AMD before symptoms appear.
Wear UV400-protective sunglasses outdoors. UV exposure increases the risk of cataracts and AMD. Polarised lenses do not provide additional UV protection unless UV400-rated.
Follow the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds. Use artificial tears for screen-related dry eye. Increase screen font size to reduce eye strain.
All diabetics should attend annual NHS diabetic eye screening (dilated fundal photography) to detect diabetic retinopathy before it causes irreversible vision loss. This is free and highly effective.
Never sleep in contact lenses. Clean lenses strictly as directed. Replace on schedule. Use sterile solution, not tap water. Contact lens keratitis can cause permanent vision loss within 24 hours.
Warm compresses applied to closed eyelids for 2 minutes twice daily improve meibomian gland function, reduce dry eye symptoms, and prevent blepharitis flares. This should become a daily habit.
Speak to a Clinician About New Floaters or Flashes
Through The GP Service, a clinician can assess new floater and flash symptoms and arrange emergency ophthalmology referral where indicated.
Expert clinical advice, when you need it.
New Floaters or Flashes FAQs
New floaters appearing suddenly, especially with flashes of light, are a warning sign of posterior vitreous detachment (PVD) and possible retinal tear. All new floaters with flashes of light require same-day urgent eye assessment to exclude retinal detachment.
Floaters are tiny clumps of collagen within the vitreous gel of the eye that cast shadows on the retina. They move when the eye moves and are particularly visible against bright or light-coloured backgrounds. Most are benign and related to normal ageing of the vitreous.
Flashes of light (photopsia) are caused by mechanical traction on the retina, as occurs in posterior vitreous detachment or retinal tear. They are typically brief, like a flash of lightning, and most pronounced in dim lighting. Any new flashes require urgent eye assessment.
Established floaters that have been present for months or years are usually benign and do not require treatment. Most people adapt to them over time. For severe persistent floaters, vitrectomy or laser vitreolysis are specialist options, but are rarely required.
Sudden shower of new floaters, especially with flashes or visual field loss (curtain or shadow across part of vision), indicates possible retinal detachment. This is an emergency — attend A&E immediately. Retinal detachment requires urgent surgical treatment to preserve vision.
Posterior vitreous detachment (PVD) is a natural ageing process where the vitreous gel separates from the retina. It causes new floaters and flashes. It occurs in most people over 60. Most PVDs are benign, but 10–15% cause retinal tears requiring urgent laser treatment.
High myopia (short-sightedness of −6 dioptres or more) is a significant risk factor for retinal detachment. Highly myopic individuals should be aware of retinal detachment symptoms and have regular dilated fundal examinations.
After PVD is confirmed with no retinal tear, a follow-up eye examination at 4–6 weeks is typically recommended. If new symptoms develop (new floaters, flashes, or visual field change), same-day urgent re-assessment is needed.