Daily Archives: September 10, 2010

ommatidium

Hmm. This word looks a bit like it has little bugs in it, doesn’t it? Those m’s crawling through it, like so many little legs. And on the other hand, if you put enough m’s together, you could get something reminiscent of an insect’s eye seen from the side: mmmmmmm, each hump a little lens.

On the other hand, it may seem a bit of a boring word; the om of meditation may make many think of mental dead space, and that is certainly given a slant by the clear echo of tedium (in fact, the whole word sounds like “I’m a tedium” or “Oh, my tedium”). Rather like a conversation with someone who keeps going on about arcana that you don’t really care about, such as what this or that little thing is called…

Oh, wait. If you’re reading this, chances are you’re one of those who go on about such things, or at least one of those who don’t find them boring. And well may it be so. In spite of the common carp “Small things amuse small minds,” the truth is that it takes a rather big mind to appreciate and take an interest in a small thing (think minimal music, or a meditative medieval Te Deum, or even a piece such as Mike Oldfield’s Ommadawn, or Zen gardens, meditation, philosophical minutiae…). Small minds (or a fool, what they call in Irish amadán) seem to go in more for big conflicts, car crashes, explosions…

Well, if you have an eye for small things, you will have an eye for an ommatidium. And it will have an eye for you. Its root, you see, is Greek omma “eye” and the diminutive suffix idion, rendered in Latin as idium (just a minor shift of idiom). It’s not a little eye, not quite, though; it’s part of a little eye – a bug’s eye. You know, you’ve seen those pictures of flies’ eyes made of many little sub-eyes. Of course you knew, didn’t you, that those sub-eyes had to have a classically derived name. Well, that name is ommatidium, plural ommatidia. Again, though, an ommatidium is not an eye; it’s part of a compound eye. And a fly has two eyes – just as ommatidium has two i‘s.

I just happened to spot this word today in an picture feature on electron microscope photos of insects. I saw it on a website. And while the concept of eyes with multiple little parts may seem strange, let’s remember that the images we see on websites are displayed on our screens in much the same way as bugs see: with many little dots. And the images have in many cases been captured by digital cameras – which have sensors that are also made of many little sub-eyes that perceive just one dot of light of one colour each. For that matter, much the same is to be found inside your eye: all those rods and cones on the retina, allowing you to see this here now.