Speaker 1: Welcome to brain Stuff from How Stuff Works a brain
Speaker 1: Stuff Christian Sager Here, Today's question is what our eyeboggers.
Speaker 1: If you've ever had to wipe gunk out of the
Speaker 1: corner of your eyes, it's not because you were visited
Speaker 1: by the Sandman or a magical mucus ferry. Nope, we
Speaker 1: live in a cruelly mundane universe, and I'm sorry if
Speaker 1: I'm the first to break it to you, But eye
Speaker 1: buggers are a build up of the pre corneal or
Speaker 1: basil tier film that coats and protects your eyes plus
Speaker 1: any foreign particles it catches. This tier film is just
Speaker 1: three micrometers thick, which is less than half the diameter
Speaker 1: of a red blood cell. But it's made up of
Speaker 1: three components, the mucin, the aqueous, and the lipid. These
Speaker 1: are indistinct layers of stuff that your body produces. The
Speaker 1: aqueous component is the operative one. It nourishes, lubricates, and
Speaker 1: fluff shows your eyes cells. It also smooths over microscopic
Speaker 1: lumps and bumps on the surface of your eyes, creating
Speaker 1: a smooth lens that optimizes light transfer into your retina.
Speaker 1: The other two components are a support system for the
Speaker 1: aqueous one. The musing component underneath it allows it to
Speaker 1: temporarily stick to your eye, and the lipid component outside
Speaker 1: it holds it in place so that you're not just
Speaker 1: you know, crying constantly. So closest to your corneal surface cells,
Speaker 1: you've got the musing component of the tear film. Mucins
Speaker 1: are the proteins that make mucus slimy. They're important in
Speaker 1: your eyes because corneal cells. Your corneal cells need water
Speaker 1: and water soluble nutrients, but your corneal cells, unhelpfully are hydrophobic,
Speaker 1: meaning they repel water like microscopic little ducks. Mucin helps
Speaker 1: out by latching onto your corneal cells, specifically via adhesive
Speaker 1: molecules called ico calyx that grow on the cell's surface,
Speaker 1: and musants are hydrophilic, meaning that they grab onto water molecules.
Speaker 1: Next up the aqueous component. As you may have guessed
Speaker 1: from the name, this layer is made up of about
Speaker 1: water plus two percent water soluble stuff. At any given time.
Speaker 1: Part of that two percent is things your corneal cells need,
Speaker 1: like electrolytes, oxygen, and antibacterial enzymes, and part is the
Speaker 1: cell's waste. There are also some musans floating around in there,
Speaker 1: and usually some dust debris, and you know sun dream microbes. Finally,
Speaker 1: topping it all off, you've got the lipid component, a
Speaker 1: k a. The me bum. It's made mostly of wax
Speaker 1: and cholesterol esters. These esters are slick, hydrophobic substances that
Speaker 1: our bodies used to lubricate and waterproof various tissues in
Speaker 1: the tier film. They float on top of the aqueous layer,
Speaker 1: helping our eyelids glide easily over our eyes. They also
Speaker 1: provide a strong surface tension for our basil tears. Without
Speaker 1: the lipid layer, our tear film would drip right off
Speaker 1: our eyeballs. But how do these components become eyeboggers and
Speaker 1: why do they accumulate in the inner corners of your eyes. Well,
Speaker 1: I'm going to tell you. When you blink, your entire
Speaker 1: eyelid doesn't close simultaneously. It shuts like a clapboard from
Speaker 1: the outer corners of your eyes inward towards your nose.
Speaker 1: Your tear film gets pushed along by that motion. Upon
Speaker 1: reaching the inner corner of your eye, most of the
Speaker 1: film drains out through the tear ducts, which empty into
Speaker 1: your nasal cavity. And some of the film. The musans
Speaker 1: and oils and debris can clump together and get stuck.
Speaker 1: When enough of that builds up, it forms the goop
Speaker 1: known as eyeboggers, and when it accumulates and dries overnight
Speaker 1: because you're not blinking it away, it forms the crusty
Speaker 1: gunk known as sleep or saying. Check out the brainstff
Speaker 1: channel on YouTube, and for more on this and thousands
Speaker 1: of other topics, visit how stuff works dot com.