The most common cause of retinal detachment is a posterior vitreous detachment, a natural age-related process in which the gel-like substance filling the eye shrinks and pulls away from the retina. This pulling can create a tear or hole in the retina, allowing fluid to seep underneath and separate it from the tissue that nourishes it. Globally, this type of detachment (called rhegmatogenous retinal detachment) affects roughly 12 people per 100,000 each year, with rates highest in Europe at about 15 per 100,000.
How the Vitreous Gel Causes Retinal Tears
The inside of your eye is filled with a clear, jelly-like substance called the vitreous. When you’re young, this gel is thick and firmly attached to the retina, the light-sensitive layer at the back of your eye. As you age, the vitreous gradually liquefies and shrinks. At some point, usually after age 50, it pulls away from the retina entirely. This separation is extremely common and usually harmless.
Problems arise when the vitreous is abnormally sticky or firmly adhered to certain spots on the retina. Instead of peeling away cleanly, it tugs hard enough to rip the retinal tissue. Once a tear forms, liquefied vitreous can flow through the opening and pool behind the retina, pushing it away from the underlying layer of cells that supplies it with oxygen and nutrients. Without that blood supply, the retinal cells begin to die, and vision loss follows.
Nearsightedness Is the Biggest Risk Factor
Severe nearsightedness (high myopia) dramatically increases the risk of retinal detachment. People with high myopia have elongated eyeballs, which stretches the retina thinner and makes it more fragile. The vitreous also tends to liquefy earlier in myopic eyes, accelerating the whole process.
The numbers are striking. The lifetime incidence of retinal detachment in highly myopic eyes (worse than -6.00 diopters) is about 3.2%, compared to 0.71% in eyes with normal vision. At extreme levels of myopia, between -15.00 and -20.00 diopters, the risk jumps to 15 to 110 times greater than average. Even moderate myopia matters: the yearly incidence rises from about 0.015% in mild myopia to 0.07% in moderate-to-high myopia and 0.075% in very high myopia. If you wear strong glasses or contacts for distance vision, this is worth knowing.
Cataract Surgery and Eye Trauma
Cataract surgery is the most common eye surgery in the world, and it carries a small but real risk of retinal detachment afterward. In a study of over 3 million eyes, about 1 in 500 developed a retinal detachment within one year of surgery. Over 10 years, the rate ranges from 0.36% to 2.9% depending on the study. The surgery changes the internal structure of the eye in ways that can destabilize the vitreous and promote earlier separation from the retina.
Eye trauma accounts for 6% to 40% of all retinal detachment cases, a wide range that reflects differences across populations and how injuries are classified. Blunt force, like a punch, a ball to the eye, or an airbag deployment, can cause the retina to tear on impact or create damage that leads to detachment weeks or months later. Penetrating injuries carry even higher risk.
Other Types of Retinal Detachment
Not every retinal detachment starts with a tear. Two less common types work through different mechanisms. Tractional detachment happens when scar tissue on the retina’s surface contracts and physically pulls it away from the back of the eye. This is most often seen in advanced diabetic eye disease, where abnormal blood vessels grow on the retina and create fibrous tissue that gradually tightens.
Exudative detachment involves fluid leaking under the retina without any tear or pull. The fluid comes from inflamed, infected, or damaged blood vessels in the layer beneath the retina. Conditions that can trigger this include severe eye inflammation, certain infections like tuberculosis and toxoplasmosis, tumors in or behind the eye, age-related macular degeneration, and pregnancy complications like preeclampsia. These types are treated by addressing the underlying condition rather than surgically repairing a tear.
Warning Signs Before Detachment
Retinal detachment is usually preceded by symptoms that, if caught early, can be treated before the retina fully separates. The classic warning signs are a sudden burst of new floaters (dark spots or cobweb-like shapes drifting across your vision) and flashes of light, especially in your peripheral vision. These flashes happen because the tugging vitreous mechanically stimulates the retinal cells, which interpret the pulling as light.
About 14% of people who show up with new floaters or flashes and are found to have a vitreous detachment also have a retinal tear. That number sounds modest, but it climbs sharply with additional symptoms. If you also notice blurred or reduced vision, the chance of a tear rises to 45%. If bleeding is visible inside the eye, it reaches 62%. A shadow or curtain creeping across part of your visual field is the hallmark sign that the retina has already begun to detach.
Why Timing Matters for Treatment
The critical distinction in retinal detachment is whether the central area of the retina, the macula, is still attached. The macula handles your sharpest, most detailed vision, and once it detaches, visual recovery after surgery drops significantly.
A large study from Japan’s retinal detachment registry found that repairing a macula-off detachment within two days of onset produced significantly better vision at six months compared to waiting even one more day. Surgery within three days still outperformed surgery at four days or later. After four days, outcomes plateaued, meaning waiting five or six days was no worse than four, but all were worse than acting within the first two to three days. For macula-on detachments, where the center of vision is still intact, surgery is typically performed urgently to prevent the detachment from spreading to the macula.
This is why the warning signs matter so much. A retinal tear can often be sealed with a quick laser or freezing procedure in a clinic, preventing detachment entirely. Once the retina fully detaches, the repair requires more involved surgery and the visual outcome becomes less predictable, especially with each passing day.