There's a hole in your vision — where is it?

Cover one eye and look around. Everything seems complete, edge to edge. But part of what you "see" never reaches your eye at all. Can we catch the gap?

1Two things to know first

Your eye is a screen of tiny sensors — with one bald patch

You need two small ideas. Watch each one happen:

The back is a sensor grid

The back of your eye is carpeted with millions of light sensors. Light that lands on them becomes a "I saw that!" signal to your brain.

One spot has no sensors

At one spot all the wires bundle up and leave the eye. There's no room for sensors there — a bare patch. Light that lands on it just… vanishes.

2It depends where the light lands

Same eye — two very different fates

Lands on a sensor 👀

The sensor fires and your brain gets the message. You see it.

Lands on the bare patch 🕳️

Nothing is there to catch the light, so no signal leaves the eye. Keep this in mind…

3Move the light around

Drag where the dot's light lands

Here's your eye from above. The orange light comes in and lands somewhere on the back wall. Slide it across and watch the signal: green when it hits sensors, and what happens when it crosses the bare patch?

Where the light lands: on sensors
LEFT WALLRIGHT WALL

signal: ON  The bare patch sits off to one side — slide across it and the signal drops to nothing.

4Now find YOUR blind spot

Cover one eye, stare at the cross — then predict

Close your left eye. With your right eye, stare hard at the white cross and don't move your eyes. We'll slide the orange dot slowly toward the cross. Keep staring at the cross the whole time.

Guess before you watch

As the dot slides toward the center of your view, what will happen to it?