Tag: Eyes

How mucus keeps us healthy – Katharina Ribbeck

How mucus keeps us healthy – Katharina Ribbeck

If you’ve got a cold, mucus is hard to miss. But what is it, and what does it do besides making you miserable? Your body produces more than a liter of mucus every day, and all the wet surfaces of your body that are not covered by skin, like your

Vision: Crash Course A&P #18

Vision: Crash Course A&P #18

Take a good long look at this — we’re gonna mess with your brain. This is the first stage of an optical illusion. Many illusions use patterns of light or perspective to exploit the disconnect that exists between sensation and perception — between what your eyes see and what your