The retina is the light-sensitive tissue lining the back of the eye. A retinal detachment occurs when it separates from its normal position. It is usually painless, but it can permanently damage vision if treatment is delayed.
The symptoms that matter most
- A sudden increase or “shower” of new floaters.
- New flashes, often described as lightning or camera flashes at the side of vision.
- A grey or dark curtain, veil or shadow moving across the visual field.
- Sudden peripheral vision loss or a new blurred area.
- A sudden change in vision after an eye injury or eye surgery.
Longstanding floaters that have not changed are common. What matters is a sudden change. A posterior vitreous detachment can cause similar symptoms and is often not itself sight-threatening, but only a dilated retinal examination can distinguish it from a tear.
Who has higher risk?
Risk is higher in people with high myopia, lattice degeneration, a previous retinal tear or detachment, a serious eye injury, a family history, or certain eye surgeries. Cataract surgery is associated with a small increase in risk. In the large U.S. IRIS Registry, retinal detachment occurred in about 1 in 500 cataract operations in patients over 40 during the first postoperative year; individual risk varied greatly and lattice degeneration was the strongest recorded factor.
This number is not a reason to avoid needed cataract surgery. It is a reason to know your personal risk and recognize symptoms. Tell your surgeon about high myopia, previous retinal laser, trauma or a detachment in either eye.
What an urgent examination involves
An ophthalmologist usually dilates the pupil to inspect the peripheral retina. Additional imaging or ultrasound may be needed if the view is limited. A retinal tear can sometimes be sealed with laser or cryotherapy before a detachment progresses. An established detachment may require surgery. The appropriate treatment depends on the location, size, macular involvement and condition of the eye.
Do not try to diagnose it at home
Closing one eye at a time may help you notice which eye is affected, but it cannot rule out a tear. Do not drive yourself if your field of vision is missing or suddenly impaired. Seek same-day professional assessment, even if the symptoms improve after lying down or seem less noticeable in bright light.
The takeaway
Most floaters are not a detachment, but a sudden new pattern must be treated as a warning until the retina has been examined. In this situation, speed protects vision.
Sources and evidence
Sources support the medical statements. The interpretation and plain-language explanations are Oleksii Sologub's.