vitreous detachment

A common cause for flashes and floaters, a vitreous detachment is when the “gel” in the back of the eye contracts inwards upon itself.  Let me explain. The eye is mostly a hollow structure.  In many ways, the eye is like a water balloon sitting inside your eye socket.  The eye is not filled with water, however, but is filled with a clear fluid called the vitreous jelly. This jelly has the consistency very much like Jell-O.  In childhood, the vitreous gel is firm and well-formed, but as we get older the gel gets “runny” and “watery.”  Little pockets of saline water form inside the gel, and while this sounds bad, it really isn’t a problem.  Both the gel and the water are clear and we can see through them just fine.  At some point in our life the vitreous gel can become so watery that one day, without warning, the remaining vitreous gel can suddenly collapse inward upon itself. This causes flashing lights and floaters. If you want to use a metaphor, think of the eyeball like a Tupperware bowl filled to the brim with Jell-O. Now, imagine what would happen if you put that bowl of Jell-O on your kitchen counter and then you went on vacation for several months. With time, the Jell-O will evaporate and dehydrate until it collapses and falls in upon itself like a big “blob” in the middle of the bowl.  A similar process happens inside the eye.  The vitreous gel peels off the retina inside the eye.  The retina detects light, so that as the gel peels off it, many people will see a flash of light like a lightning bolt in their peripheral vision.  In addition, many people complain of a new, large floater in their vision. This occurs when a little bit of cellular debris pulls off the optic nerve as the gel peels away from it. This little piece of junk is now floating inside the eye, hovering at the gel-water interface, casting shadows inside the eye that you can see as the gel wobbles around.  In rare cases, the vitreous gel can actually rip a small hole in the retina itself.  This is bad, because a retinal hole can extend and turn into a full-on retinal detachment with loss of vision.  Anyone with new symptoms of flashing lights or new floaters needs a dilated eye exam to look for these retinal tears.  If the initial retinal examination shows a healthy retina, I usually have my patients return in a few weeks for a recheck to make sure nothing new has formed.  The flashing lights and floaters will diminish with time, though the floater can sometimes take a long time (months or years) to disappear (and sometimes it never does entirely).  There is no safe way to make these floaters go away short of a vitrectomy surgery (not recommended).