Floaters and Flashes
Spots and cobwebs float in your vision, or sudden flashes of light appear—usually harmless but sometimes need urgent checking.
A way to think about it
The inside of your eye is filled with clear gel (vitreous). Floaters are tiny clumps of gel or cells casting shadows on the retina—like dust specks floating in front of a projector's light beam. Flashes occur when the vitreous pulls on the retina, stimulating light-sensing cells. Most are benign, but occasionally a flash warns of a retinal tear.
What's happening in the eye
Floaters are shadows cast by tiny clumps of debris inside the vitreous gel. These occur naturally as the gel ages and liquefies, and cells clump up. Flashes happen when the vitreous gel shrinks and tugs on the retina. As you age (usually after 50-60), the vitreous gel pulls away from the retina (posterior vitreous detachment, or PVD). Most PVD is harmless and just causes more floaters and occasional flashes.
Common symptoms
- Small dark spots, lines, or cobwebs floating in vision
- Shadows that follow eye movements but lag behind
- Flashing lights in peripheral vision, especially at night or in dim light
- In PVD: sudden burst of floaters over days to weeks
- After a shower of floaters: possible brief dark shadow or curtain edge
Risk factors
- Age over 50—vitreous gel naturally ages and shrinks
- High myopia (nearsightedness)—longer eyes have earlier vitreous degeneration
- Prior eye surgery or laser treatment
- Eye inflammation (uveitis) from any cause
- Diabetes—especially if diabetic retinopathy present
- Vitreous hemorrhage (bleeding into gel) from diabetes, retinal tear, or injury
Warning signs - seek care immediately
- Sudden shower of floaters or flashes—URGENT: see retina specialist today or ER if not available
- Dark curtain or shadow creeping across your field—this is likely retinal detachment, ER now
- Floaters accompanied by pain or vision loss—don't wait, get ER evaluation
- New floaters after eye surgery or trauma—get urgent eye exam
Questions to ask your doctor
- 1.Did my eye doctor do a dilated exam? Did they see any retinal tears or risk areas?
- 2.Should I use an Amsler grid to self-monitor for retinal problems?
- 3.If new floaters appear, how quickly should I seek care?
- 4.Is my high myopia (or diabetes) putting me at higher risk for retinal problems?
- 5.If my floaters become bothersome, am I a candidate for laser or vitrectomy?
Most floaters are a natural part of aging and harmless. Sudden floaters with flashes or shadows need checking urgently, but if no tear is found, reassurance is all you need. Adaptation comes quickly.
Sources
Information on this page is based on the following authoritative sources:
- American Academy of Ophthalmology
- National Eye Institute (NIH)
- American Optometric Association
- Mayo Clinic
Last updated: April 2026