--- title: Eyes and ears deeper: glasses, colour blindness, tears, earwax and dizziness — a lesson of Mova's school · trees and pragmatics description: «Eyes and ears deeper: glasses, colour blindness, tears, earwax and dizziness», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Your eyes and ears are not just windows and holes: they are clever machines with lenses, wipe --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / Eyes and ears deeper: glasses, colour… # Eyes and ears deeper: glasses, colour blindness, tears, earwax and dizziness Lesson 362 of the biology course of Mova's primary school: 16 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/0/) — Your eyes and ears are not just windows and holes: they are clever machines with lenses, wipers, drains, pipes and tiny spirit levels, and the brain quietly fixes their faults so you never notice. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/1/) — Think of spinning round in the playground and stopping: the world keeps turning because fluid inside your ears is still swirling, like tea that keeps going round after you stop stirring. - [2](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/2/) — When a part works a little differently, such as an eyeball that is too long or colour cells that mix up red and green, things look blurry or the same, and glasses or a few tricks help. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/3/) — Many of these parts work together, so when eyes and ears tell the brain different stories, as when you read in a moving car, you can feel sick. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/4/) — In short sight the eyeball is a little too long, so pictures of far things come into focus in front of the back of the eye, and a glasses lens bends the light so the focus lands in the right place. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/5/) — More children are short-sighted now than 50 years ago, and many scientists think too little time outdoors in daylight is part of the reason. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/7/) — The eye has three kinds of colour cells, for red, green and blue light; in colour blindness one kind works differently, usually making some reds and greens hard to tell apart. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/8/) — About 1 boy in 12 is colour blind but only about 1 girl in 200, because of how the gene is passed on; a test of coloured dots with a hidden number finds it. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/9/) — Every eye has a blind spot where the nerve leaves and there are no light cells; the brain fills in the hole, and an octopus eye, wired the other way round, has none. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/10/) — Cutting an onion lets out a gas that stings the eye, and reflex tears wash it away; there are also everyday tears that keep eyes wet and tears when you feel sad or very happy. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/11/) — Tears drain through two tiny holes at the inner corner of each eye into the nose, which is why your nose runs when you cry. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/12/) — Most people blink about 15 to 20 times a minute, each blink spreading tears like a wiper; staring at a screen makes you blink much less, so eyes feel dry. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/13/) — Earwax traps dust, helps keep germs out and moves out by itself as you chew and talk; cotton buds often push it deeper, and one gene decides whether it is dry and flaky or wet and sticky. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/14/) — Deep in each ear are three curved tubes full of fluid, set at right angles like the corner of a box, that tell the brain when the head turns. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/15/) — In car sickness the inner ear feels the car moving but eyes on a page say everything is still; looking out of the front window at the horizon helps them agree. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/362-eyes-and-ears-deeper-glasses-colour-blindness-tears-earwax-and-dizziness/16/) — A thin tube joins each middle ear to the back of the throat to let air in and out; on a plane, swallowing, yawning or chewing opens it, and a cold can block it and make ear pain worse. - ← previous: [Growing up: growth spurts, height, voices and getting stronger](https://md.mova.elamur.ai/free/en/corpora/school/biology/361-growing-up-growth-spurts-height-voices-and-getting-stronger/) - next →: [Sleep and dreams in people](https://md.mova.elamur.ai/free/en/corpora/school/biology/363-sleep-and-dreams-in-people/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)