A retinal detachment is a very serious problem that usually causes blindness unless treated. The appearance of flashing lights, floating objects, or a dark or light shadow in a corner of your vision are all indications of a retinal detachment. f any of these occur, see an eye doctor right away.
As we age, the vitreous (the clear, gel-like substance that fills the inside of the eye) tends to shrink slightly, forming clumps within the eye. What you see as floaters are the shadows that these clumps cast on the retina, the light-sensitive nerve layer lining the back of the eye.
The appearance of flashing lights comes from the gentle tugging (or traction) of the vitreous gel on the retina. Flashes may look like twinkles, lightning streaks, or a flash of light from a camera.
When the vitreous shrinks, it can pull on the retina and cause a tear. A torn retina is a serious problem. It can lead to a retinal detachment and blindness. Fluid can pass through the tear and then lift the retina off of the back of the eye like wallpaper peeling off a wall. Laser surgery or cryotherapy (freezing) is often used to seal retinal tears and prevent detachment.
If the retina is detached, it must be reattached. There are three ways to repair retinal detachments. Pneumatic retinopexy involves injecting a special gas bubble into the eye that pushes on the retina to seal the tear. The scleral buckle procedure requires the fluid to be drained from under the retina before a flexible piece of silicone is sewn on the outer eye wall to give support to the tear while it heals. Vitrectomy surgery removes the vitreous gel from the eye, replacing it with a gas bubble, which is slowly replaced by the body’s fluids.
If new floaters appear suddenly or you see sudden flashes of light or you see shadows in your vision or your vision changes, see an eye doctor immediately.