Eye floaters: when they're normal and when you should run

What they really are

The eye is filled with a transparent gel called the vitreous. With age (or with myopia) the gel slowly liquefies and forms tiny condensations — threads, dots, cobwebs — whose shadows project onto the retina. That's what you 'see' floating, especially against a clean sky or a white screen.

The large majority are harmless and chronic: they annoy you for a while, then the brain learns to ignore them (yes, really).

The three red flags — learn them

These three signs can mean a retinal detachment: the only treatment is urgent, surgical, ophthalmological. Golden rule with no exceptions: with any of them, eye emergency care THE SAME DAY. The retina does not send second warnings.

• 1A sudden shower: many new floaters appearing within hours or days.
• 2Flashes of light (photopsias) at the edge of vision, especially in the dark.
• 3A curtain, a fixed shadow, a loss of part of the visual field.

And the ones you already have — can anything be done?

In most cases, nothing — and that's actually good news: the real treatment (vitrectomy, removing the gel) is risky and reserved for very selected disabling cases. Laser vitreolysis has very narrow indications. The hopeful part: neural adaptation works. Months later, most patients say they 'no longer see them' even though they're still there.