Thursday, February 21, 2008

iZon: First Impressions on HD eyeglasses

Seems like everything is going for high-definition nowadays, and apparently eyeglasses are no exception. A company named Ophthonix came out with "high-definition" lenses. Then their marketing department went nut-so on it and the world got iZon®, which supposedly uses an iPrint(tm) of one's eye to give one WOW(tm) vision. (I was a bit disappointed when the glasses didn't come in an iCase with a WOWlenscleaningcloth. Ah, well, can't have everything.)

So, what is a high-definition eyeglass?
Marketing aside, the idea behind iZon® is really neat. As far as I understand, they use a scanner to measure the optical correction needed at several thousand points on each eye (I vaguely remember my doctor throwing the number 16,000 around), instead of the usual method (which is basically an average measurement of the correction needed and, much like physics problems in school, relies on the assumption that the eye lens and the retina are perfectly smooth in their imperfections).

The following is mostly my guess at how they do this... Having that map, they then create a lens that gives the average correction, but that contains a polymer film sandwiched in the middle of two halves. That film can be adjusted on a point by point basis to locally alter the optical properties of the lens and correct for the that particular person's eyes. The company's site offers a marketing version of how iZon® works.

The site claims great, wondrous feats of magic will happen if you get one of these high-definition lenses. Well, not really, but the visual marketing is quite amusing (check out the WOW-o-meter at the bottom of the linked page).

My very own high-definition eyeglasses
In any case, the marketing worked well enough that I went and got myself one of these made. I've now been wearing my very own high-definition eyeglasses since yesterday.

Am I seeing better than before?

Yes, definitely. Images are crisp, vivid, &c. But it's hard to tell how much of that is due to an updated prescription and wearing eyeglasses that haven't collected four years' worth of scratches. Now, they also gave me a plot of the local adjustments needed on my prescription and, it turns out, my eyes aren't that far from the ideal (if horribly near-sighted) eyes. Since there isn't that much variation, then my normal lenses probably weren't doing too badly by me.

Another benefit claimed by these lenses is that they may reduce flaring/glare/halo'ing around bright lights (especially on car headlights at night).
Of course, that means I've spent the past two evenings walking around staring at bright lights. (Yea, bright idea, haha. But oddly difficult to stop doing.) I haven't noticed a huge improvement, but that isn't to say that the image isn't great. I'm still trying to figure out a good way to do tests on this one (nothing useful yet, but I do now have a series of vaguely amusing photos taken through eyeglasses... it's kinda fun to see what I can get by focusing my camera lens really close, then shooting something far away through the eyeglasses... I suppose it's a good demonstration of just how incredibly near-sighted I am :) ).

Any disadvantages?
Well, although these lenses don't seem any heavier than my previous ones, they are thicker. From what I remember, the refractive index on these is 1.68, versus the current standard for high refractive index lenses at 1.74 (what I had before). [Aside: the higher the refractive index of the material, the thinner the lens can be for the same optical correction.]

I'm guessing that they went for the lower refractive index as an attempt to reduce chromatic aberration on these lenses (since so much of their selling point is visual clarity and crispness even in high-contrast scenarios), though it may also have something to do with the process of locally adjusting the prescription.

To sum it up -- your mileage may vary, but at the very least these lenses seem to provide good results. And, if normal lenses have been cheating you out of the optical correction you need, you may actually find some WOW(tm) in these. :)

1 comment:

sled dog said...

just got me a pair. chromatic aberration is still significant so i'll probably go back to contacts.