• Question: why do we blink?

    Asked by hughgreer007 to clairemarieroberts, Faye, Martin, Mus, Pete on 24 Apr 2012.
    • Photo: Pete Etchells

      Pete Etchells answered on 24 Apr 2012:

      Hi hughgreer007! Brilliant question. We blink to keep our eyes wet – if we didn’t keep pushing tears around the surface of the eye, it would dry out, and that would make it more likely to get scratched or irritated by a bit of dirt or dust. Any scratches like that could potentially become a place for bacteria to hide, which might mean you get something called ‘conjunctivitis’, which can be very painful.

      There are other reasons we blink, though. Deliberately blinking one eye (winking) is a way of communicating with someone else without speaking to them, which can be quite useful in lots of complex different ways. You can give people a lot of information with such a small body movement!

    • Photo: Faye Didymus

      Faye Didymus answered on 25 Apr 2012:

      Hi hughgreer007 – great questions on the live chat! To answer your question about blinking…there are many reasons why we blink…
      1) Blinking automatically supplies two forms of moisture to our eyes, to keep them from drying out, and to keep foreign matter from entering and irritating our eyes. Eyelids themselves, our built-in “wind-screen wipers” and are controlled by muscles capable of expanding and contracting so rapidly, that blinking does not impair our vision. Mother Nature lined the rims of our eyelids with 20-30 sebaceous, oil-producing glands, which are located between our eyelashes, and are invisible to the naked eye. Blinking automatically coats the eyelid and eyelashes with the lubricant it secretes, to prevent them from drying out.

      2) Blinking also shields the eye from foreign bodies. Our eyelashes serve as dust-catchers, as the blinking reflex causes them automatically to lower when exposed to dirt and dust and stuff. Nature endowed the camel with extraordinarily long, curly, eyelashes, to protect his eyes from sudden sandstorms in the desert!

      3) Blinking also protects the eye from dryness by cleaning the eye, The eyelid, through suction, automatically draws the fluid we cry with from the the tear duct over the eyeball to clean and moisturise the eye.

Comments