Here's a crazy fact about your body from Daily Mail  you probably never knew.  Because of how our brains work, how good your vision is varies throughout the day.

Scientists in Germany tested people's eyesight at different points in the day.  And it was slightly better around dusk and dawn than it was in the middle of the day.  And it's because of how our brains process what we're seeing.

Around 8:00 a.m. and 8:00 p.m., some of the background activity that's going on in your visual cortex calms down, so it's easier to pick up visual signals.  Specifically, dim light.  Which makes it easier to identify objects in the distance.

The study found there was a 26% drop in activity compared to midday.  And they think it's a product of our evolution.

Thousands of years ago, we needed to see better at dusk and dawn, because that's when we were more likely to be attacked by predators.

Once we started living in cities and figured out how to use electricity, we didn't need it anymore.  But the results of our evolution are still with us.  So our vision is best around dusk and dawn, and worst around 2:00 p.m.

You've probably never even noticed it before, so it's obviously not a huge difference.  But if you really want to ace your next eye test, maybe schedule it for the morning or evening instead of on your lunch break.