Sudden Black Spots in Vision Not Floaters: Causes & When to Worry UK

If the spots drift and trail a moment after your eye stops moving, they are almost certainly floaters — clumps in the vitreous gel that are common and usually harmless. What should make you pause is something different: a fixed dark patch that stays put when you move your eye, a sudden shower of tiny black dots or specks like soot, or a shadow creeping in from one side. Any of those can mean a retinal tear, bleeding in the eye or a blocked blood vessel, and each needs a same-day eye examination.

Spots, floaters or a fixed shadow?

It helps to notice how the spot behaves, because that is often the biggest clue. A true floater moves with your eye and keeps drifting for a second after you stop — it’s a shadow cast onto the retina by something floating in the gel, so it never sits still. A scotoma, on the other hand, is a fixed dark or missing patch in one part of your vision that doesn’t move with your gaze. That difference matters: a fixed patch is more likely to come from the retina or the optic nerve itself.

A sudden burst of many small black dots is a third pattern again. When new dots appear like a cloud of pepper or soot, that can be red blood cells released into the vitreous — a vitreous haemorrhage. Cover one eye and then the other for a few seconds; knowing whether the problem is in one eye or both is one of the most useful things you can tell the clinician.

When new black spots are an emergency

Get an urgent, same-day eye assessment — through a private clinic, your optometrist, or an NHS eye casualty unit — if any of these come on suddenly:

A shadow or dark curtain moving across or up from the bottom of your vision
Flashing lights alongside the new spots
A shower of new black dots that wasn’t there yesterday
A fixed dark or blank patch in the centre or side of your sight
Any sudden drop in vision, blurring or distortion in one eye

One situation needs more than an eye clinic. If a dark patch or a “curtain coming down” arrives with slurred speech, a facial droop, or weakness or numbness on one side, treat it as a suspected stroke and call 999. A brief loss of vision in one eye that clears within minutes (sometimes called amaurosis fugax) can be a warning sign too, so ring NHS 111 or your GP the same day even after it settles.

New spots, flashes or a spreading shadow? A dilated retinal examination checks for a tear or bleed so it can be treated before your sight is affected.

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What causes new black spots that aren’t floaters

Several things can put a genuinely new dark spot in your vision. The examination is really about telling the harmless ones from the few that need treating quickly:

Retinal tear or detachment — the vitreous tugs on the retina and tears it; fluid can then seep behind the retina and lift it, which is what the “curtain” represents.
Vitreous haemorrhage — bleeding into the gel, often from a torn retinal blood vessel or from diabetes, seen as a sudden cloud of dots or a reddish haze.
Retinal vein occlusion — a blocked vein in the retina can cause a sudden blurred or dark area, and may need injection treatment.
Macular problems — a fixed central spot or a patch where straight lines look bent can point to the macula, as in wet AMD.
Migraine aura — a shimmering or zig-zag patch that grows and then clears within an hour, usually in both eyes, and typically nothing to do with the retina.

Diabetes deserves a special mention. If you have diabetic changes at the back of the eye, a fragile vessel can bleed with little warning, so new floaters or spots in a diabetic eye should always be checked rather than watched.

How the cause is found

The heart of the visit is a dilated fundus examination: drops widen the pupil so a consultant ophthalmologist can look at the whole retina, right out to the edges where most tears hide. If the view is clear and the retina looks healthy, that is genuinely reassuring. Where more detail is needed, an OCT scan images the macula in cross-section, a visual field test maps any missing patch, and a B-scan ultrasound is used when bleeding is too dense to see through. Because blood pressure and the circulation matter here, the clinician may check those too, or point you back to your GP for them.

If your spots came with flashes or a sudden change, our same-day flashes and floaters check is built for exactly this — a focused examination to rule out a tear the same day.

What happens next

What follows depends entirely on what the examination shows, and for most people it is good news. If the retina is intact and the spots are ordinary floaters or a settled vitreous detachment, you’ll be reassured and told which symptoms would mean coming back. When a retinal tear is found, it can usually be sealed with laser in a short outpatient visit, which greatly lowers the chance of a detachment. A detachment that has already happened, or heavy bleeding that won’t clear, is treated surgically — see our overview of vitreoretinal surgery. Vein occlusions and macular conditions are managed on their own pathways, often with injections. The thread running through all of it is simple: the sooner the cause is known, the more the options.

Frequently asked questions

Are black spots in my vision the same as floaters?+

Not always. Floaters drift and trail when your eye stops moving, because they are shadows from clumps in the vitreous gel. A black spot that stays fixed in one part of your vision, a sudden shower of tiny dots, or a spreading shadow behaves differently and can point to a retinal tear or bleeding, so a new or changing spot is always worth checking.

When should I go to A&E for black spots in my vision?+

Seek same-day help if a shadow or dark curtain spreads across your sight, if you get flashing lights with the spots, or if vision suddenly drops in one eye. Many areas have an NHS eye casualty unit, or a private clinic can see you urgently. If the visual change comes with slurred speech, a facial droop or one-sided weakness, call 999, as these can be signs of a stroke.

Can sudden black spots be a sign of a stroke?+

They can. A dark curtain over part of your vision, or a brief blackout in one eye that clears after a few minutes, can reflect a problem with the blood supply and is sometimes a warning of a stroke. If it comes with other stroke symptoms, call 999; if it settles on its own, still contact NHS 111 or your GP the same day so the cause can be looked into.

What does a fixed black spot in one part of my vision mean?+

A dark patch that stays put when you move your eye is called a scotoma, and unlike a floater it doesn’t drift. It can come from the retina, the macula or the optic nerve, so it needs a proper examination rather than watchful waiting. A dilated exam and often an OCT scan will show where the problem sits and how it should be managed.

How are the causes of new black spots diagnosed?+

The key test is a dilated fundus examination, where drops widen the pupil so the whole retina can be checked for tears, detachment or bleeding. Depending on what’s found, an OCT scan of the macula, a visual field test or a B-scan ultrasound may be added. Together these usually identify the cause in a single visit.

Sudden black spots in your vision that aren’t floaters