Retinal detachments, while rare (affects about one in every 15,000 people), are very dangerous and can cause blindness in a matter of days. While usually spontaneous, people who are very nearsighted or have had previous eye injuries or surgeries are more susceptible to retinal detachments.
There are three main types of detachments: exudative, tractional, and rhegmatogenous. Exudative retinal detachments are caused by fluid leakage underneath the retina, usually from a tumor, birth defect, or inflammatory disease. Tractional retinal detachments are caused by pulling on the retina from within, usually from scar tissue. Rhegmatogenous retinal detachments occur because fluid within the eye enters a hole or tear and causes the retina to separate from the inner wall of the eyeball.
When the retina is getting tugged on, you can often see a flash of light. Depending on how hard the tug and how often, the light flashes can vary in intensity and frequency. If the traction is successful in creating a hole or tear, you can often see a "floater" or even a shower of "floaters" in your vision. "Floaters" look like spots or strings in your vision and can vary in size, shape, and opacity. Once a hole or tear is formed, there is a passageway for fluid to enter it. As fluid enters and the retina separates from the wall of the eyeball, you will lose vision in that area. Depending on how much fluid enters, you may notice either extreme darkness or a subtle change in your peripheral vision. It is often described as a "cloud" or "curtain/veil" that starts to form in your peripheral vision and usually spreads towards your central vision. This vision loss is painless.
The best way to check for a retinal detachment if you have any symptoms is to get a thorough eye exam with dilation right away. The best way to prevent a retinal detachment is to get regular eye examinations with dilation to check for any holes or tears before they allow fluid to enter. The earlier a hole/tear/detachment can be detected, the more likely it can be repaired simply with laser or freezing therapy rather than a complicated scleral buckle procedure or a vitrectomy.
