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eye conditions

Eye floaters and vitreous detachment

Drifting spots are not dust on the eye. They are shadows of your own vitreous. Most are harmless — but there are four signs you do not wait until morning for.

Short answer

Floaters are shadows cast on the retina by collagen condensations inside the vitreous. With age the vitreous liquefies, shrinks and pulls away from the retinal surface — that is posterior vitreous detachment, and it happens to most people. Drops do not remove them and usually nothing needs doing, because the brain adapts. But a sudden shower of floaters, flashes that will not stop, a dark curtain at the edge of vision, or loss of central vision mean a retinal tear or detachment, and then every hour counts.

Have you noticed, looking at a bright sky, a white wall or a screen, small grey spots, threads, cobwebs or transparent bubbles drifting across your field of vision? When you move your eye, they follow with a lag and settle slowly, and blinking does not wipe them away.

These are commonly called floaters, and medically vitreous floaters. In most cases they are the natural ageing of the gel inside the eye. With certain symptoms, though, they can point to a retinal tear or detachment, which needs care immediately.

Vitreous: floaters.

What the vitreous is, and why floaters form

About 80% of the volume of the eyeball is filled by a transparent, gel-like substance called the vitreous. It is 99% water and 1% collagen fibres and hyaluronic acid, which hold the eye in shape and let light reach the retina unobstructed.

In a young eye the vitreous is completely clear and uniform. With age, usually from about 40 to 50, its structure begins to change.

  1. Liquefaction. The gel begins to turn liquid and shrink. Medically, synchysis.
  2. Collagen clumps. The transparent collagen fibres running through the vitreous clump into microscopic, denser strands.
  3. Shadows on the retina. As light enters the eye, those clumps cast a shadow on the retina. What a person sees is not microbes or dust on the eye, but the shadows of their own vitreous.

Posterior vitreous detachment and flashes

In a young eye the vitreous is attached to the retinal surface by fine fibrils. As it ages and liquefies, the vitreous shrinks in volume and slowly separates from the retina. This physiological event is called posterior vitreous detachment, or PVD.

It is a normal age-related process occurring in most people between 50 and 70, and earlier in people with high myopia. Two symptoms typically come with it.

  • A sudden increase in floatersAs the vitreous separates from the area of the optic disc, a denser ring-shaped bundle of fibres forms — the Weiss ring — which can appear as a larger drifting cobweb or ring.
  • Flashes of lightWhen the shrinking vitreous mechanically pulls on the retina, the brain registers that stimulus as light. People see streaks, sparks or camera-flash bursts in the dark or when moving their eyes. Medically, photopsia.
Vitreous: detachment.

Red flags: when not to wait

Most floaters are harmless. A detaching vitreous can, however, cause a complication: as it pulls, it can tear the retina — a retinal tear. If liquefied vitreous fluid then gets under the retina through that tear, the retina starts peeling away from the back of the eye. That is a retinal detachment, and delayed treatment means permanent vision loss.

Seek emergency eye care immediately if you notice

  1. A sudden shower of floaters. Dozens or hundreds of new black spots, or a soot cloud, appearing at once.
  2. Frequent, intense flashes of light. Persistent streaks in the corner of the eye that do not stop.
  3. A dark curtain or shadow in the field. A dark shadow, curtain or wall creeping in from the edge toward the centre. That indicates a detachment already in progress.
  4. Sudden blurring or loss of central vision.

With these symptoms the right place is an emergency eye service or a hospital emergency department, not the next available appointment. Every hour counts.

Who gets this earlier

  • High myopiaA longer eyeball stretches both vitreous and retina more, which brings vitreous detachment and retinal tears forward — often into the thirties and forties.
  • Eye traumaBlows to the head or the eye.
  • Previous eye surgeryCataract surgery, for instance, changes vitreous dynamics.
  • Intraocular inflammationUveitis.
  • Diabetic retinopathyCan cause bleeding into the vitreous, which appears as sudden black patches. In a person with diabetes, any new black patch needs a prompt check.

How floaters are examined

The state of the vitreous and the retina can only be assessed with a dilated fundus examination. The doctor instils dilating drops and examines vitreous clarity under the microscope, then checks the integrity of the whole retina to rule out micro-tears in the periphery that are invisible otherwise. Without dilation, it is exactly that part of the retina — where tears most often form — that goes unexamined.

Can floaters be treated

Adaptation and monitoring · the gold standard

For ordinary, harmless floaters no treatment is given. The brain adapts to the drifting shadows, and over time the denser clumps settle lower in the vitreous and become less noticeable.

Advantage. No risk. For most people this genuinely is enough.

Limitation. Requires patience: adaptation takes weeks to months.

Laser vitreolysis · YAG laser

Larger, bothersome clumps are broken into smaller particles with a laser.

Advantage. Outpatient, without opening the eye.

Limitation. Done rarely and only against specific criteria: the clump must sit in a suitable position, well clear of both the retina and the lens.

Vitrectomy · intraocular surgery

The vitreous is removed surgically and replaced with a sterile solution.

Advantage. Removes the floaters definitively.

Limitation. Intraocular surgery, carrying the risks of cataract and retinal detachment. Reserved for the most severe cases.

Laser for a retinal tear · barrier laser

A fresh retinal tear is sealed to the back of the eye with a laser to stop the retina peeling away.

Advantage. Prevents a detachment when the tear is found in time.

Limitation. This is not a treatment for floaters — it prevents the complication.

Laser vitreolysis.

What KSA does

With floaters, KSA's job is to answer one question: is this ordinary ageing or something else? The Audit eye examination assesses the retina, the vitreous and the fundus. If fresh retinal tears or dangerous vitreous traction are found, that is dealt with before any laser procedure — it is not an optional step.

If the retina and fundus are healthy and the vitreous changes are natural and stable, floaters are no obstacle and the Flow3 surface procedure can go ahead. Flow3 itself neither causes nor removes floaters: it works in the surface layers of the cornea, while the vitreous sits deep inside the eye.

Closely related: myopia — a high minus is the main risk factor for floaters and retinal tears — and cataracts.

We examine in Tallinn and Tartu.

faq

Frequently asked questions

No. Eye drops and artificial tears act on the outer surface of the eye, the cornea and conjunctiva. Floaters sit deep inside the eye, in the vitreous. No drop or supplement can dissolve collagen clumps in there.

Bright light makes the pupil constrict, like a small aperture on a camera. A small pupil gives greater depth of field, so the collagen clumps cast a much sharper, clearer shadow on the retina. You are not getting more floaters — they are simply more visible.

Flashes mean the vitreous is physically pulling on the retina. That often accompanies an ordinary posterior vitreous detachment, but a dilated fundus examination is still needed to confirm the traction has not caused a retinal tear. You cannot judge this yourself: tears usually sit in the periphery, where you see nothing.

Reading and screen use do not cause or worsen floaters. Heavy lifting and straining do raise pressure in the eye and head, and in people with a fragile retina that can contribute to a tear if the vitreous is already pulling on it.

Flow3 is performed in the surface layers of the cornea; the vitreous sits deep inside the eye. Flow3 neither causes nor removes floaters. After getting rid of glasses, some people notice floaters a little more against their new, sharper picture — that is an optical effect, not a change inside the eye.

This is a medical emergency. A dark curtain or wall at the edge of the field indicates a retinal detachment in progress. Go immediately to an emergency eye service or a hospital emergency department — every hour counts in saving vision.

Have the back of your eye examined

New floaters or flashes are a reason to come in. A dilated examination gives the answer. Tallinn and Tartu.

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