Sunday, October 01, 2006

...forced to find out

I just stumbled over why there is a word verification (aka captcha) which keeps robots from posting comments to these blogs even though only registered users can post at all: There were enough of those that post automated 'nice article, here's my blog'. State of the humanity: Disgusting?

And yesterday we were shopping for shoes. We came over a nice pair that was unfortunately only available in 36 (yeah, we have strange sizes over here) and not in her size. We then decided on another pair, and I wonder if we later will find out that we don't actually like them that much and instead have only transferred our liking of the first pair to everything in the shop. Well, at least they costed less than the lunch beforehand. (We also have strange habits regarding relative opulence of lunch and dinner.) State of the humanity: Easily fooled?

And would you believe that people willingly buy stuff that is more expensive and less functional just because it is a bit better looking? Ok, it happens with shoes all the time, but I'm talking of glasses now. Last round I selected an open frame, which means no glass lenses because of danger of damaging. So, plastic was required, and the clerk quickly talked me into aspherical lenses which he said were thinner, due to being aspherical and also due to being available with a higher refractive index. A lot of time went by until they arrived (which is another story and not related to any complex production process). And then they turned out to be simply shitty. The regular glasses had a field where everything goes blurry, and the sun glasses had a bit of that nearly everywhere except when looking exactly straight through. Now, I intend to do viewing around by moving my eyes, not my head.

As it turns out, 'aspherical' is not the same as in photographical lenses. There the surfaces are not exactly spherical because their properties can be improved by slight, but properly computed deviations. In glasses, however, they simple start to flatten out the lenses from the (basically) correct spherical form so that they don't end up being so thick at the rim. This means simply that the lenses do not work properly in some areas! And you get sold that as an advantage: The lenses are indeed slightly slimmer, but more expensive and less functional. I wonder how anyone would want to live with that who has has proper lenses before. (Someone who gets her first glasses may however think that the imperfect correction is unavoidable, never having seen it better.)

Only good thing is that these days the shops offer full refund if there is anything you don't like about the glasses. I had other glasses made for the regular frame (at no extra cost), returned the other, ordered sunglasses in another shop (also spherical), neglected to specify exact kind of glass and thus spent an extra minor fortune on those, got two glasses that work everywhere I can look through them, and learned a lot more about spherical, cylindrical and prismatical refraction, eye distance yaddayadda that I wanted to know. But you need to know to get glasses you want to wear.

Funnily I hear a lot of people complain about colored borders (aka chromatic aberration) but I hardly ever notice those, and I don't mind them.

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