There’s a place in the eye where the nervous system meets the retina. That area can’t detect light. There’s a simple experiment you can do that will show you where it is.

What blows my mind is you have to try to see it. It’s not a black spot. It’s a blank spot. Same color as the background. Your mind fills it in with what it assumes must be there.

There are conditions that make it obvious. When I have a migraine (it’s been a while thank God), I can’t see what’s in the very middle. I had a migraine on press day once. Reading words on a screen was excruciating. I could only see the edges of whatever I looked at. Luckily I spent a little time in a dark office and it went away.

The old woman I met on a Greyhound bus once, was an even more extreme example. She said she couldn’t see the middle of anything. It sounded pretty disabling, but she seemed to get a kick out of it.

“I looked out the window at my little weenie dog yesterday and he was just a dog’s head attached to a tail,” she said. “Then he turned to look at me and he disappeared. Haw haw.”

I’ve been pondering what all that implies. First of all, it’s always possible you could miss little things, just because you literally can’t perceive them.

You don’t even have to get into how we can’t see infrared or ultraviolet. There are just… holes in our perception. Our brains hide them from us.

If a critter had been riding on that woman’s dog, she never would’ve seen it.

If you have reasonably good eyesight, it isn’t likely that anything you need to see will be hiding in your blind spot. But it could.

We can only see, hear, feel and taste what our bodies will allow. There will always be a layer between us and what’s truly there.

What else is the mind filling in for us?