Isekonia, you say 'wha?'

August 25, 2010 9:41 AM

Attention glasses/contacts wearers! Do you have a major difference in the prescription between one eye and the other, aka anisometropia? Have you found any benefit from iseikonic lenses?

So, the theory goes that when people who have a difference in the refracting power of their eyes get glasses, the magnifying power in each lens is slightly different, and so the final result is an imperfect image that leads to persistent visual deficits, tiredness, etc., unless the lenses are made in such a way as to compensate for these differences. The optometrist linked above doesn't seem to be a huckster, but I'm curious if anyone's had any practical experience getting iseikonic lenses versus regular lenses and if it's made any difference.

posted by greatgefilte to health & fitness (7 answers total)

When I worked in a lab making eyeglasses (grinding the prescription into the lens etc.), each lens would be created for each particular eye with it's unique prescription. Have +4.25 in your right and +7.25 in your left? Then we'll make one lens of each. It's a non-issue.
posted by arjuan at 9:59 AM on August 25, 2010

I have a large difference between my two eyes (-1.25, -5.75) and wear glasses with regular lenses without any problems (except that because the magnification in one lens is so much greater, one eye looks smaller and I have what I call "Picasso face"). All my life, optometrists told me I could never wear glasses because the difference was so great. Then one day, I met an optometrist who didn't see why I couldn't wear glasses, and I've had six delightful years of comfortable wear.

I'm saying, based on my experience, that I would be highly skeptical of an optometrist who told me that because of the difference in my eyes, I can't wear glasses without difficulty.
posted by prefpara at 10:32 AM on August 25, 2010

My glasses reduce the size of everything I see by at least 40%. It's a huge difference. If you had one eye as myopic as mine are, and one that was not nearly as bad, the size difference in the images would have to be a significant problem. You simply can't focus two images together when one is 40% smaller than the other!

However, when I wear my contact lenses, the size of the images through the lenses is the same as when I'm wearing no corrective lenses at all. Contact lenses should therefore be a good way to avoid anisometropia. They also cost a small fraction as much as my glasses do. (I wear glasses with a spherical correction of -10.5 diopters; my contact lenses, for the same clarity of vision, are -9.0 diopters.)
posted by Ery at 11:14 AM on August 25, 2010

I have a fairly large difference (most recently -8.25 and -6, I think; enough for weight on one side to be an issue) and they didn't do anything special for me - if they had tried I would have made them stop; the darned things cost $600 as it was. I get headaches if I'm tired or stressed and have been using the glasses too much (in the sense that wandering around in familiar places for 30 minutes without glasses ends the headache.) I had no idea there was something you could do to fix this. If it weren't half a paycheck, I'd try it.
posted by SMPA at 12:01 PM on August 25, 2010

I'm -3.0, -6.0 and have been similarly lopsided for ~25 years. Aside from my optometrist always greeting me with his head tilted all the way to the right (mocking my lopsidedness), there has never been a mention, let alone an issue, with getting anything other than standard lenses for my glasses.
posted by bluejayway at 12:26 PM on August 25, 2010

"You simply can't focus two images together when one is 40% smaller than the other!"

Not true in my experience. Also, everything my left eye sees is tilted to the side, and everything my right eye sees is not. Yet my brain has no problem merging the two, my depth perception is great... these problems may only exist for you in theory. Give cheap, standard glasses a try.
posted by prefpara at 1:31 PM on August 25, 2010

I have a big disparity in prescription, and I've worn standard glasses for 25 years or so. The result is that I suppress the vision from the weaker eye. I've never heard of these glasses you've described---and it seems strange that none of the multiple optometrists I've seen over the years would have mentioned them! But maybe they're great.

For what it's worth, I just started wearing contacts, and it does seem to be helping me use both eyes at the same time.
posted by leahwrenn at 2:44 PM on August 25, 2010