Eye floaters: what they are and why they appear

Look at a light-colored wall and catch out of the corner of your eye a spot that disappears as soon as you try to look at it. Floating spots, threads and cobwebs are familiar to very many people. Usually this is a harmless phenomenon, but sometimes it hides a problem that requires a prompt examination.

What eye floaters are

Floaters (muscae volitantes) are structures of various sizes and shapes that appear in the field of vision and move when the eye moves. The cause is clouding of the fibers of the vitreous body: a person sees them as threads, "balls of wool," dots, grains, knots or needles. The vitreous body is not a homogeneous fluid but a gelatinous substance made of hyaluronic acid and a network of collagen fibers, normally completely transparent. When individual fibers thicken and lose transparency, floating opacities, or floaters, appear in the field of vision. Patients call them cobwebs, dashes and dust in the eyes.

Why floating floaters appear in the eyes

The most common cause is age-related changes in the vitreous body, which usually begin at 40–60 years of age. Posterior vitreous detachment (PVD) often becomes the cause: the gel inside the eye changes, and the process itself is harmless. Sometimes the cause is more serious — retinal detachment. Other possibilities: myopia, vascular disorders, endocrine and metabolic changes (puberty, pregnancy, hormonal medications), diabetes mellitus, head, eye and nose injuries along with surgeries, physical exhaustion, prolonged eye strain, prolonged stress, past infections, toxoplasmosis. Some floaters appear without an obvious cause.

What the specks in the eyes look like and when they are more noticeable

Floaters look different: small dark dots, wavy lines, rings, cobwebs, "balls of wool." In older people with impaired cholesterol metabolism and diabetes mellitus, crystalline inclusions occur — "silver" or "golden rain." They are best seen against a bright, uniform background: the sky, snow, an illuminated white wall or ceiling, and also when squinting. In dim light and a variegated environment, floating floaters are usually not noticed. It is difficult to focus the gaze on a particle: it shifts along with the movement of the eye. Opacities due to vitreous destruction are always visible in light and keep a stable shape — unlike the "negative" after looking at the sun or sparks when lifting weights, changing pressure, or a blow to the head.

Which signs are considered alarming

Alarming signs are associated with a sharp change in the picture. An urgent examination is needed if:

• floaters or flashes of light have appeared for the first time;
• their number has suddenly increased;
• a dark "curtain" or shadow moves across the field of vision;
• vision has become blurred or eye pain has appeared;
• floaters began after eye surgery or injury.

This can be how a problem with the back of the eye manifests, which without prompt treatment permanently worsens vision. Retinal detachment is an emergency condition; people over 40 and those who are very nearsighted, have retinal detachment in the other eye or in the family history, have undergone cataract surgery, other eye diseases, or eye injury are more prone to it.

The presence of floaters alone is not a reason to call an ambulance. 103 or 112 — if a dark veil or "curtain" moves across the field of vision.

How an ophthalmologist determines the cause of floaters

The eyes are examined by an ophthalmologist; they decide which additional examinations are needed. To see the fundus, drops that dilate the pupil are instilled into the eye. During biomicroscopy, the doctor also notices shiny crystalline inclusions, if present. The decision on treatment is made by the doctor, and usually it is needed only for a problem that may affect vision.

A quick self-check that does not diagnose anything but helps describe the picture at an appointment: how many floaters there are, whether they are the same in shape and size, whether there are flashes of light, whether a shadow covers part of the field of vision. If the picture changes, it is better not to delay the examination.

The volume and type of opacities usually stabilize several months after appearance, the flashes may stop over time, and the person gets used to the floaters and notices them less often. Dense opacities sometimes noticeably worsen the quality of life, although working capacity usually does not suffer.

The material is for reference and does not replace a doctor's consultation: it is possible to understand what exactly is floating in the field of vision only during an examination.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer