Of all the cool things that eye doctors use to test people's vision, none is a better indicator of what's going on in the retina than this simple grid devised by Professor Marc Amsler in 1945.
Cover one eye and focus the other on the dot in the center of the grid:
I had three different people proofread the graphic before I sent it off. No spelling mistakes, just an incorrect date that wasn't spotted. Anyway, they're back from the printer and they look great. Hope you can make it to the show. Just don't show up on the 24th.
Cover one eye and focus the other on the dot in the center of the grid:
What do you see? And what don't you see? What's great about the Amsler Grid is that we know that it's a grid—a big square made up of smaller, evenly-sized squares separated by horizontal and vertical lines. But is that what you see? Try it with the other eye.
When I look at an Amsler Grid, here are the sorts of things that happen for me:
To my eyes, entire line segments are missing and others are distorted into moving, twisting shaped, indicating blind spots in the retina. Some of this is normal—the optic nerve occupies a chunk of space in the human retina causing a blind spot in everybody's eyes. The Amsler Grid lets us know where that spot is, and any distortion is what the brain does to fill in the gap.
My grid is bit more extreme because of the dystrophy in my retinal cells, and while the Amsler Grid demonstrates that clearly, it's also happening to everything I look at, including more irregular shapes like printed words.
If you've read this blog, you've probably seen my typos and articles about them, and this week I had two more that were costly: The poster for CONES came back with "donation" spelled "doantion". No big deal—I'd only printed a dozen. But when 500 palm cards showed up with the wrong date on them, I had to fork out for a reprint:
JUNE 24 = WRONG DATE |
JUNE 23 = CORRECT DATE |