Sunday, while in one of my meetings, it happened again; this time the whole right side of the room became one large blind spot to where I could only see the other brethren in the room if I turned and looked directly towards them. This lasted about twenty minutes and there was the prismatic effect that went along with it. Later that evening I had a terrible headache which might have been related.
I mentioned it to Lucy and she booked an appointment with the ophthalmologist which is where we spent most of Monday. I found that my eyes are in good shape; no broken or damaged parts, other than normal aging. I’d described what I had seen to the nurse and the doctor and learned that what I’d experienced isn’t that uncommon; just a little un-nerving when it happens the first time.
I looked Ophthalmic Migraine up on the Internet when I got home and here is the section along with a graphic which went along with the article. While the image doesn’t do it justice; it does give an idea as to what it looked like. Mine looked it was a tunnel with little prisms circulating around the edge and anything outside the circle to the right was no longer visible.
Migraine headaches may be preceded by a visual "aura", lasting for 20 to 30 minutes, and then proceeding to the headache. Some people, however, experience the aura but do not have a headache. This visual aura can be very dramatic.
Classically, a small blind spot appears in the central vision with a shimmering, zig-zag light inside of it. This enlarges, and moves to one side or the other of the vision, over a 20 to 30 minute period. When it is large, this crescent shaped blind spot containing this brightly flashing light can be difficult to ignore, and some people fear that they are having a stroke. In reality, it is generally a harmless phenomenon, except in people who subsequently get the headache of migraine. Since migraine originates in the brain, the visual effect typically involves the same side of vision in each eye, although it may seem more prominent in one eye or the other.
Some people get different variations of this phenomenon, with the central vision being involved, or with the visual effect similar to "heat rising off of a car". Some people describe a "kaleidoscope" effect, with pieces of the vision being missing. All of these variations are consistent with ophthalmic migraine.