Most of us pick up a few floaters as we get older: the specks, threads or cobwebs that drift across your vision against a bright sky or a white wall. They are usually harmless. But there is a version of this that is not harmless at all, and the difference between the two can come down to a single afternoon.
A sudden shower of new floaters, flashes of light at the edge of your vision, or a dark curtain creeping across one eye are not part of normal ageing. They are the classic warning signs of a retinal tear or detachment, and they need to be looked at the same day. Here is what changes in the eye after 50, which symptoms are genuinely urgent, and where to go in Ireland when they happen.
TL;DR
- Floaters are shadows cast by the vitreous gel inside the eye. They become more common after 50 as the gel shrinks and pulls away from the retina, a process called posterior vitreous detachment (PVD).
- Most PVDs are harmless, but roughly one in ten people with sudden floaters and flashes turns out to have a retinal tear, which can lead to a sight-threatening detachment.
- Four red flags mean same-day assessment: a shower of new floaters, repeated flashes of light, a shadow or curtain across your vision, and any sudden drop in vision.
- Timing changes the outcome: a detachment treated before it reaches the macula, the centre of your detailed vision, has a far better result.
- In Ireland, a community optometrist is usually the fastest first stop. For a curtain, shadow or sudden vision loss, go straight to an eye casualty or emergency department.
Why floaters multiply after 50
The back chamber of the eye is filled with vitreous, a clear gel sitting against the retina, the light-sensitive tissue lining the inside of the eye. From midlife the gel liquefies and its collagen fibres clump together, casting shadows on the retina. That is what you actually see, which is why floaters look worse against bright backgrounds and dart away when you look straight at them.
Eventually the shrinking gel peels away from the retina altogether. This is posterior vitreous detachment (PVD), and it happens to most people at some stage, typically between 50 and 75. It usually announces itself over a few days with a jump in floaters, sometimes a single large ring or blob, plus brief arcs of light in the side vision.
On its own, PVD needs no treatment: the floaters settle over weeks to months. The problem is that as the gel separates it can tug hard enough to tear the retina, and a tear lets fluid track underneath and lift the retina off the wall of the eye. That is retinal detachment, and it does not repair itself. Because an uncomplicated PVD and a PVD with a tear feel identical, the only way to tell them apart is a dilated examination. You cannot self-diagnose this one, and neither can a GP without the right equipment.
The four symptoms that need same-day attention
- A shower of new floaters. Not an extra speck noticed over a year, but a distinct burst: dozens of dots, a swarm of black pepper, a smoky haze. A dense shower can mean bleeding from a torn retinal blood vessel.
- Flashes of light. Brief arcs, streaks or lightning-like flickers in the side vision, often repeating and more obvious in the dark. They come from traction pulling on the retina, which the brain reads as light.
- A shadow, curtain or veil. A dark area encroaching from one side, above or below, that does not clear when you blink. This suggests the retina has already begun to detach. It is an emergency.
- A sudden drop in vision. Any abrupt loss or blurring in one eye, painless or not, needs urgent assessment rather than a wait-and-see approach.
A useful habit: cover each eye in turn now and again. Plenty of people only find a problem in one eye by accident, because the good eye has been compensating for weeks.
Why the clock matters
A retinal tear caught early can often be sealed in an outpatient clinic with laser treatment or freezing (cryotherapy), which takes minutes and usually prevents detachment entirely. Once the retina has detached, the treatment becomes surgery.
Surgeons describe detachments as “macula-on” or “macula-off”. The macula is the small central part of the retina responsible for reading, faces and fine detail. If the detachment has not reached it, prompt surgery has a good chance of preserving sharp central vision. Once the macula has lifted, the retina can usually still be reattached, but central vision often does not return fully. Hence going in today rather than at the weekend.
Who is at higher risk
Anyone can develop a retinal tear, but the odds rise if you are short-sighted, because the eyeball is longer and the retina thinner. Risk also increases after cataract surgery, after a blow to the eye or head, if you have had a detachment in the other eye, and where there is a family history. Diabetes carries separate retinal risks, which is why Diabetic RetinaScreen exists, though that is not a general eye test.
Other sudden vision changes worth recognising
Not every eye emergency involves flashes and floaters. Three others are worth knowing by their pattern:
- Sudden painless loss of vision in one eye, like a shutter coming down, can be a blocked retinal artery, effectively a stroke of the eye. Ring 112 or 999.
- A new persistent headache with scalp tenderness and jaw pain when chewing, in someone over 50, can signal giant cell arteritis. Same-day assessment protects the other eye.
- Straight lines such as door frames or tiling appearing wavy is the hallmark of wet age-related macular degeneration, which is treatable when caught quickly.
Where to go in Ireland
For new floaters and flashes without a curtain or vision loss, a community optometrist is usually the fastest route. They can dilate your pupils, examine the peripheral retina, and refer into hospital ophthalmology if a tear is found. Ring and ask for an urgent dilated retinal examination, using the words “flashes and new floaters”. Most practices will fit you in that day or the next.
For a curtain, shadow or sudden loss of vision, go straight to an emergency department. The Royal Victoria Eye and Ear Hospital in Dublin runs a dedicated eye emergency service, and regional hospitals with ophthalmology units have on-call cover. Bring your glasses, your medicines list and details of any previous eye surgery.
On cost: with the qualifying PRSI contributions, the Treatment Benefit Scheme covers a free eye examination every second year, and medical card holders can access community ophthalmic services through the HSE. One practical warning: dilating drops leave you blurred and light-sensitive for hours, so bring sunglasses and arrange a lift home rather than driving.
What is not an emergency
Floaters you have had for years that have not changed. Mild blur that clears when you blink, usually tear film rather than retina and often dry eye. Gradual dimming over months, more likely cataract. These belong at a routine eye examination, not in an emergency department.
The real risk in later life is the opposite instinct: putting a sudden change down to “just my age” and waiting a fortnight to mention it. Age is a risk factor for retinal detachment; it is not an explanation for a curtain across your vision. At Críonna Health we return to this point often, because eye departments would far rather see ten uncomplicated vitreous detachments than miss the one tear that was fixable this morning.
This article is for general information and is not a substitute for individual medical advice. If you have sudden changes in your vision, contact an optometrist, your GP or an emergency department without delay.
📷 Photo by Age Cymru on Unsplash
