Anatomy Atlas Part 22 – Eye

For humans the eyes are probably one of the most important senses. They are definitively for me, so two years ago when a willow twig slashed me across one eye the pain was a mere secondary concern to the fear that an infection might cost me the whole eye. I did not hesitate and immediately sought medical help, got antibiotics and atropine and the eye healed in just a few weeks. Ever since then I am wearing eye protection when pruning willows, in addition to all the other jobs I am used to do so.

Description of an unpleasant  and cringe-worthy incident follows.

©Charly, all rights reserved. Click for full size.

Incidentally just a few days ago I had a short conversation with the cleaning lady at our lab about this. I have made some mess that I did not manage to clean up before she arrived to mop the floors and I was apologizing to her for this. Her response was that it is her job to clean the floors and mine was that I know but that is no reason for me to do her job unnecessarily harder by not sweeping the aluminum shavings after I am done. After which she remarked in a passing that her former boyfriend was drilling aluminium when doing some renovations, he was too macho to wear an eye protection and got an aluminium shaving in one eye. And after that he was too macho to go to the doctor immediately, saying “it will rot away”.  And it did. With the whole eyeball. She finished “now he has one glass eye, and I have found myself a better man.”.

An example of how toxic masculinity is harmful, if I ever saw one.

Most people know at least something about the eye anatomy I guess, but I would bet most people do not know about the muscles musculus obliquus bulbi superior and musculus obliquus bulbi inferior.

These muscles can rotate the eyeball slightly around the front-back axis. Why is this? you might ask.

Generally the muscles around the eye, when you are looking at something, try to keep the picture you see static and at the center of focus, even when you move. So when you look at your monitor right now and tilt your head to left and back, your eye bulbs will rotate in the sockets in such a way as to keep the light falling on the same parts of retina throughout. That is also one of the reasons why human eyes cannot “pan” like a camera, but always skip from point to point.

It was explained to us that the purpose of this is to save the brain from getting overloaded with constantly changing stimuli. When the eye is fixed, it delivers constant signal to the brain from most of the retina, and the brain then can concentrate only on that which is really important – i.e. that which changes on its own.

I do not have the knowledge to challenge this notion, but I must say that the brain-software that keeps the eye focused and immobile relatively to the thing we are looking at must be pretty impressive too, with all those feedback loops reacting so quickly as they do.


  1. Ice Swimmer says

    They did surgery to my eye muscles three times in the space of ten years when I was a kid and I still have a bit of strabismus. They would have done a fourth operation, but I said no. Probably just as well, because I almost suffocated on anesthesia at the third time.

    I remember my Mom’s husband once cutting sheet metal (for the roof of Grandpa’s place) without any eye protection and when somebody asked him if goggles might be a good idea, he just scoffed. After cutting a while he did get a spark in the eye (and it clearly hurt), but luckily he didn’t lose his eyesight or eye.

  2. says

    Partner had her cataracts done a few years ago, what amazed her was that post op she could see colour like she had never seen before. The artificial lenses are just that much clearer than the old ones. Her favourite jumper got tossed once she realised what a horrible tinge of pink it was instead of a nice muted grey.

  3. rq says

    I’ve been wearing glasses since I was about 10 because near-sightedness runs in the family (the teacher was writing something on the blackboard -- I could see her writing, and I realized I couldn’t see what she was writing, it was invisible…), and sometimes I wonder what it’s like to see everything clearly without squinting (or without glasses, ha). I did find that I had excellent twilight vision, without the glasses -- something about the lack of bright light actually made it harder to see (distinguish shapes and shadows) with glasses, so most evening skiing I did without them. These days I wear them for driving, TV, and getting on the right bus, but once I’m in a familiar environment (home, work) I’m far more comfortable without.

  4. avalus says

    Ouch, that story hurts just from reading. My great grandfather had a glass eye*, for me it was therefore normal that people would have a eye in a glas next to their beds. False teeth on the other hand were utterly nighmarish for young me.

    *From the War of course. He was staunchly antifashist and socialist as long as I knew him and told me about many things that he experienced during the regime. He would be heartbroken today.

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