A few weeks ago I began experiencing an odd disturbance in the vision of my right eye. It started off as a kind of flickering in the upper right periphery whenever I moved the eyeball within its socket - never when I held the eye fixed and turned my head. But if I panned from right to left, I'd see this flickering in the corner of my vision.

It was at the end of a long workday (12 hrs or so), and I chalked it up to fatigue. It was present the next morning, but much less pronounced, so I thought that was the end of it.

But over the next several days, it came back. It seemed to wax and wane in severity, and change its character. Now when it happens, it's as if a large floater in my eyeball sweeps rapidly across my field of view, not quite obscuring my vision, but flashing translucently by. At other times, the vision is just filmy, as though looking through a gossamer-thin sheet of waxed paper. Blinking sometimes clears it up. Sometimes not.

I have one of those home medical advisor books, the first few hundred pages of which are devoted to flowcharts for self-diagnosis. When the weekend rolled around and I was still bothered by the symptoms, I had a look. Here's where following the yes-no trail led me:

"Have you had a recent head injury?"

(No)

"Have you suddenly lost some or all of the field of vision in one or both eyes?"

(No)

"Has your vision become blurred?"

(Not sure what they mean by blurred - let's tentatively say Yes)

"Is only one eye affected?"

(Yes)

"Is the eye painful?"

(No)

CONSULT YOUR PHYSICIAN WITHOUT DELAY! YOU MAY HAVE RETINAL DETACHMENT!

(Yikes! No blurriness, nope, none at all!)

"Have you developed double vision?"

(No)

"Have you been seeing flashing lights and/or floating spots?"

(Yes)

CONSULT YOUR PHYSICIAN WITHOUT DELAY! YOU MAY HAVE RETINAL DETACHMENT!

Holy crap, a detached retina! This was scary, but since this was a weekend, and I couldn't be sure if this were a medical emergency or not, I waited antsily until Monday before calling my doc to set up an appointment. I also declared a moratorium on researching the disorder - I was frightened enough, I didn't need to know more when there wasn't anything I could do about it.

When I called my physician, my expectation was that he'd schedule an appointment for a few days out, and that would be that. Instead, I was asked if I could get there within the hour.

I did, but a cursory examination by the Physician's Assistant revealed no signs of detachment, which was a relief. Still, there was enough concern to schedule an appointment with an ophthamologist later that same week. Here's the dilly:

The retina is the light-sensitive wallpaper lining the inside of the eyeball. When it starts to peel away, there is a progressive - and permanent - loss of vision.

The space inside the eyeball is filled with a gel called the vitreous humor. This gel isn't free-floating, but physically bonded to the outer surface of the retina. As we age (and I'm crowding Six-Oh hard), the gel can shrink, pulling away from the retina as it does. This is called (deep breath) "posterior vitreous detachment", and this is what is disrupting my vision. Instead of rotating in lock-step with my eyeball, blobs of this gel are flapping and folding over where it's broken loose, creating the floaters and disturbances I've been seeing. Once it's completely detached, the symptoms should disappear.

However, until it does, I'm at elevated risk for a full-blown retinal detachment, because the gel tugs at the retina each time I move my eye. So for the next few months I've got to see the ophthamologist every week or so to make sure the retina doesn't start to tear. If it does, surgical intervention will be necessary. So I ain't out of the woods yet.