Wednesday, 6 February 2008

Double vision

As I have mentioned not that long ago in this blog, during our Xmess holidays I purchased a cheap pair of Ray Ban Aviator lookalike sunglasses. At a cost of $20, it was a worthwhile purchase when I had a few days of driving ahead of me while my proper sunglasses were left behind at home. I knew that even the cheapest sunglasses are UV protected, so I took the plunge.
The thing about those cheap sunglasses I got was that I actually liked them. They look good, they're light, they're comfortable, and at their cost they make buying the real thing the ultimate act of stupidity. I felt like I managed to eat the cake and have it.
Then I noticed that I started getting headaches after wearing the cheap glasses. I noticed they made me feel as if I'm floating.
I started examining them the way I know to assess camera lenses, and indeed quickly enough I found that they offer a pretty distorted view of the world: the center bit is fine, but the closer you get to the edges the more you get the famous barrel effect that you get on the cheaper wide angle camera lenses (as per the attached diagram, courtesy of photozone.de, showing the distortion on the Nikon lens I used most frequently). The effect is worse when the sunglasses are moved disproportionately to your own movement, as might happen when walking briskly. Effectively, things that seem to be at your side are not really where you would expect them to be, while things directly at the front are; your eyes communicate this information to the brain, while your middle ears communicate slightly different info. Hence the floating feeling while walking, and hence the headaches.
I tried the same test on my Oakleys. They featured slight distortion, but nothing of the cheap sunglasses' magnitude. The pair of Persol glasses I have had a significant problem, reaffirming the uncomfortable feeling I get while wearing them.
Then I got to the most interesting test: I went to a shop and tried the real deal Ray Ban Aviators. To my surprise, they were the standout performers: solid picture all the way, hardly a shred of distortion; much better than the Oakleys, although with their flatter lenses they definitely have an easier task ahead of them.
The point of this story is that while some times you do get charged for the brand name and only for the brand name, as is often the case with clothes, with sunglasses this does not seem to be the case; your money does buy you quality, although the level of quality varies and the marginal benefit you gain with your extra money is definitely of the diminishing type. Still, between feeling good and having a headache, I'd go with opening my wallet wider.
Now, did I mention that you can get the Ray Bans for $130 at Amazon, and that the Australian dollar is currently very favorably exchanged against the green buck?

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