Eye floaters and flashes (black dots)

More about eye floaters

It sounds alarming, but the truth is, eye floaters are usually harmless. You might notice them more in the morning, when looking at plain surfaces, or after reading or rubbing your eyes. Flashes are often nothing serious, but they can sometimes be a sign of a bigger issue, like a tear or detachment in the retina. If you notice flashes, you should get them checked urgently.

What causes eye floaters and flashes?

Floaters and flashes are often harmless, but some can signal a bigger issue. 

• Posterior vitreous detachment (PVD): This is the most common cause of eye floaters and flashes. PVD happens naturally as we get older; the gel inside the eye (vitreous humour) starts to shrink and pull away from the retina. You might notice floaters that look like threads, dots, or cobwebs drifting across your vision, sometimes with flashes at the edges. It usually settles over time and doesn’t need treatment.

• Retinal tear or detachment: In some cases, the shrinking vitreous gel can tug too hard on the retina and cause a tear, which can lead to retinal detachment if left untreated. Watch out for a sudden shower of floaters, flashes of light, or a shadow or dark curtain in your vision. This is an eye emergency and needs treatment straight away to prevent permanent vision loss. Retinal tears can often be sealed with laser treatment. If the retina has detached, surgery is needed. 

• Vitreomacular traction: Sometimes, the gel in the eye pulls on the central part of the retina (the macula) instead of separating cleanly. This can cause blurred vision and flashing lights. Vitreomacular traction is more common in people with other eye conditions and may need treatment if the pulling is severe.

• Ocular migraine: Flashes or zig‑zag patterns in your vision,  sometimes with blurry patches or temporary loss of sight, could be a sign of an ocular migraine. Ocular migraines often pass on their own, but can feel unsettling if you’ve never had one before. If you’re not sure, it’s worth getting checked.

Other causes of eye floaters and flashes

Floaters and flashes can also be linked to other eye conditions like diabetic retinopathy or inflammation in the eye. These are less common, but they may need treatment with eye drops, injections, laser or surgery, depending on what’s causing them. 

Learn more about diabetic retinopathy

How are eye floaters and flashes treated?

Floaters are usually nothing to worry about and often settle on their own without treatment. In some cases, laser treatment (called vitreolysis) can be used to break them up and make them less visible, though it’s not suitable for everyone. For more severe cases, surgery (a vitrectomy) might be considered. This involves removing the gel inside the eye and replacing it with a clear solution. 

If there’s damage to the retina, laser therapy or other types of surgery may be needed. If you notice any sudden changes or if your vision is affected, don’t ignore it. Get your eyes checked as soon as you can. Regular eye tests are the best way to keep on top of things. 

Floaters and flashes can sometimes be a sign of a more serious issue, like a retinal tear or detachment. If they come on suddenly, especially if you also notice flashing lights, blurred vision, or a dark shadow in your sight, get urgent medical help. These symptoms need to be checked straight away.