Today's interesting fact has to do with sight.

While those of us who have sight, take it for granted, we don't see as much as we think we do.

We blink about every 5 seconds, which takes about 150 milliseconds.

Studies have shown that when we blink, we don't see, but the visual cortex edits out these blackouts so we never notice them.

About three times a second and lasting up to 200 milliseconds our eyes make jerky moves which are called saccades.

These movements allow the Fovea, to focus on different parts of our environment and to provide the information to the brain that then fills what we see.

During each of these saccades, while the eyes keep transmitting data to the brain, the brain doesn't process about 100 milliseconds of the information.

The average individual will perform up to 15,000 saccades a day and even if we don't include the blinking, this means that while awake and having our eyes open, our visual system is offline for up to four hours every day.

Tomorrow I'll try cover why we still think we see during these four hours.