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Floaters and flashes of light
Most floaters are harmless and permanent. A sudden increase in them, especially with flashes, is one of the few eye symptoms that genuinely needs looking at within a day or two.
Written and medically reviewed by Dr. Loi Thanh Mai, O.D.
Doctor of Optometry · Certified in the treatment and management of ocular disease · Last reviewed September 2026
A sudden shower of new floaters needs a dilated exam within 24 to 48 hours
Particularly if it comes with flashes of light, or a shadow or curtain in your peripheral vision. That combination can mean the retina has torn. A tear caught early is sealed in a short outpatient procedure; a tear that progresses to a detachment becomes surgery. Call 714-542-2226 and say you have new floaters and flashes.
What floaters can mean
Floaters come from changes inside the eye, not from the surface. Most are harmless, but a sudden increase in floaters can sometimes signal a retinal problem that needs prompt evaluation.
Age-related vitreous changes
The eye is filled with a clear gel called the vitreous. As it changes with age, tiny strands can cast shadows on the retina that appear as spots, threads, or cobwebs.
Posterior vitreous detachment
As the vitreous naturally separates from the retina, patients may notice a sudden increase in floaters or occasional flashes. This becomes more common with age.
Retinal tear
Sometimes the vitreous pulls strongly enough on the retina to create a tear. New floaters, flashes, or other sudden visual changes should be evaluated promptly because a tear can progress to retinal detachment.
Retinal detachment
A retinal detachment occurs when the retina separates from the tissue beneath it. Warning signs can include a sudden increase in floaters, flashes, or a curtain or shadow moving across the vision. This requires urgent treatment.
Vitreous hemorrhage
Bleeding into the vitreous can cause a sudden shower of dark spots, haze, or markedly reduced vision. It can occur with retinal tears, diabetic eye disease, and other retinal conditions.
Migraine aura
Migraine aura can cause shimmering lights, zig-zag patterns, or moving visual disturbances that may be mistaken for retinal flashes. Because new visual symptoms can have different causes, an eye exam may be needed to tell them apart.
Floaters that need checking, not watching
Floaters that have drifted around for years are rarely a problem. A sudden change in them is one of the few eye symptoms where timing genuinely matters, because a retinal tear caught early is a far smaller problem than one found late.
- A sudden increase in the number of floaters
- Flashes of light, particularly new ones
- A curtain or shadow anywhere in your field of view
- Floaters alongside any loss of vision
- New floaters if you are significantly nearsighted
- New floaters if you have diabetes
- New floaters after a blow to the head or eye, or after recent eye surgery
Questions patients ask
The floaters themselves generally stay, but become far less noticeable. They settle out of the direct line of sight over months and the brain progressively filters them out.
For most people treatment is not worth it. Vitrectomy removes the gel but carries real risks including retinal detachment and cataract, so it is reserved for severe cases.
The retina can only send one kind of signal to the brain: light. When the vitreous gel tugs on it mechanically, the brain interprets that pull as a flash.
On their own, no. The concern is never the floaters themselves — it is whether the event that produced them also tore the retina. That is a fifteen-minute question to answer.
Yes. A longer eyeball means a thinner, more stretched retina, so nearsighted patients develop PVD earlier and carry a higher risk of tears.
New floaters or flashes?
Call us today. A dilated exam settles the question quickly, and the reassurance is worth the appointment.