![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
threemonkeysI was at the optometrist today when I noticed something strange. I've been getting regular annual checkups at this optometrist for the last 9 years. When you get your eyes checked you read letters off an eye chart. I realised today that I have always read the letters on the chart from right to left. Any other time, like the rest of you, I read left to right.
The optometrist never comments on it. From that I suspect it happens fairly quite frequently.
Puzzled?
I was, until I realised something. The eye chart is reflected in a big mirror. It is a way to increase the effective distance from the eye to the chart in a fairly small room. Subconsciously I'm aware of the mirror and trying to make a reading adjustment even though all the letters have a vertical mirror symmetry (i.e. A, W, Y, T, V, X, O, H, U, I M only). That means that deep in my brain, something is attempting to adjust for a symmetry transform. It is interesting that it is so deep. Humans have really only had reliable mirrors since Roman times I think - far too short a time for an evolutionary adjustment to have come from that source. Even bronze age mirrors still make it a very short time in evolutionary biology terms but I can't see that they are good enough anyway to trigger the need and anyway, there wasn't a lot of writing about then. Therefore it must be something else - a conditioned reflex perhaps. Or perhaps it is just me. I did spend a big chunk of my life looking at symmetry transforms after all
The optometrist never comments on it. From that I suspect it happens fairly quite frequently.
Puzzled?
I was, until I realised something. The eye chart is reflected in a big mirror. It is a way to increase the effective distance from the eye to the chart in a fairly small room. Subconsciously I'm aware of the mirror and trying to make a reading adjustment even though all the letters have a vertical mirror symmetry (i.e. A, W, Y, T, V, X, O, H, U, I M only). That means that deep in my brain, something is attempting to adjust for a symmetry transform. It is interesting that it is so deep. Humans have really only had reliable mirrors since Roman times I think - far too short a time for an evolutionary adjustment to have come from that source. Even bronze age mirrors still make it a very short time in evolutionary biology terms but I can't see that they are good enough anyway to trigger the need and anyway, there wasn't a lot of writing about then. Therefore it must be something else - a conditioned reflex perhaps. Or perhaps it is just me. I did spend a big chunk of my life looking at symmetry transforms after all
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
no subject
Date: 2007-12-01 04:41 am (UTC)No comments please about it being the only thing I'm aware of - the truth might hurt ;-)