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