If you see dark specks or flashes of light, it's possible you could have posterior vitreous detachment (PVD), an eye problem many people have as they age.
As you get older, a gel inside your eye -- called vitreous gel -- can shrink. It can slowly detach (pull away) from your retina. That's the nerve layer in the back of your eye that helps you focus on the images you see.
Vision problems caused by PVD usually get better over a few weeks. In fact, many people don't have any symptoms, so they may never know they had it.
But for other people, PVD can cause health issues, such as bleeding and tears. If it's not treated in those cases, it can lead to permanent vision loss if the gel is detached from your retina.
Causes
Your vitreous gel is mostly made of water. For much of your life, it's right up against your retina at the back of your eye, near your optic nerve. Tiny fibers attach the gel to your retina.
As you get older, little pockets can form inside this gel. The tiny fibers that hold it to your retina can break. That can cause it to pull away from your retina and optic nerve. As a result, you can get a tear in your retina or a hole in your eye nerve.
Most people get PVD at age 50 or older, and it's very common after 80. It happens to men and women equally.
If you're nearsighted, have had cataract surgery, or had some kind of trauma to your eyes, you could be at higher risk for PVD.
Symptoms
It doesn't happen in all cases, but PVD can cause changes to your eyesight.
You may start to notice tiny dark spots that move around in your vision. They can look like flying insects, hairs, or cobwebs. These are called floaters, and they're the most common symptom of PVD.
It's normal to have mild floaters from time to time. But if you suddenly notice lots of them, it could be PVD.
Other signs are flashes of light and darkness around the edges of your vision. These could be a sign of a tear or detachment in your retina, which is often a medical emergency.
You may notice symptoms in only one eye. But if you get it in one eye, you'll likely get it in the other within a year.
Diagnosis
You should get an eye exam every year even if you don't have symptoms or wear glasses or contact lenses. It can help your doctor spot problems like PVD early on, and that can help protect your vision.
Your doctor may use drops to make your pupils (the holes in the center of your eyes) bigger and use a slit-lamp test to look for signs of PVD. This is done with a microscope that looks through the front of your eye. It can also show if PVD has caused bleeding, a torn retina, or something else that could harm your eyesight.
Your doctor also may use other tests to make sure the gel hasn't pulled away from your retina. These include:
- Optical coherence tomography (OCT) -- a 3-D scan of the inside of your eye
- Ocular ultrasound -- a test that uses sound waves to show the inside of your eye
Treatment
The floaters or flashes usually get better within 3 months, but you should have another dilated eye test 3 months after your diagnosis to make sure there isn't any new damage to your retina.
If you still have severe floaters after a few months, your doctor may give you the option to use a laser to reduce the floater or have surgery to take out the vitreous gel and clear the floaters.
If you have a retina tear, laser surgery or cryopexy, which freezes the tear, can repair it.