armb: Dog jumping in water (Default)
[personal profile] armb
Optical elements that change their refractive index because of an applied electric field aren't particularly new. But actually building them into a wearable pair of glasses is.

Well, it still looks a bit vapourware-ish, but it's an intriguing possibility. And the potential for going badly and permanently wrong should be much less than the "fix underlying short sightedness with laser surgery, then use reading glasses" approach. (I don't need bifocals yet, but no doubt the time will come. I might try going back to contact lenses again first.)

(but see also )

(no subject)

Date: 2010-06-21 02:04 pm (UTC)
From: [identity profile]
I'm personally quite happy with varifocal lenses which change focal distance from driving distance (at the top) to screen distance (the middle) and reading distance (the bottom). The idea of having the distance changed electrically sounds like a recipe for disaster - what happens if e.g. you're driving, the battery fails, and you suddenly can't see clearly at any distance?

(no subject)

Date: 2010-06-21 03:09 pm (UTC)
From: [identity profile]
My guess would be that you make sure that the no-voltage state is focus at infinity (but that doesn't rule out glitches leaving you unfocused in other failure modes).

(no subject)

Date: 2010-06-21 02:40 pm (UTC)
From: [identity profile]
Like [ profile] ffutures, I get on with varifocals with no problems, having worn them for a couple of years, now.

I got a pair when I found I was beginning to have problems reading smallish print in artificial light - I was fine during the day, or with my reading lamp behind me, but buggered when reading packet instructions in the kitchen.

As I had trepidations about them, I also got a pair of normal glasses. Peversely, I had the "normal" lenses in a quite expensive and hard-wearing frame, with the varifocals in something a bit cheaper, as I thought I would only be wearing them around the house.

However, within a couple of weeks, I found I was wearing my varifocals all the time, including driving, without a problem.

As a result, my varifocal frames are now wearing out a bit, and I am about to go back to the optician to ask them to drop the same (or similar) varifocal prescription into my other frames.

(no subject)

Date: 2010-06-21 03:18 pm (UTC)
From: [identity profile]
I want ones which know what I'm looking at and focus on that *g*. Oh, they're called "working eyes", I'll have some of those.

I use all of my visual area for everything, and so don't get on with fixed varifocals. I don't want to have to look down through the glasses at what I'm reading, nor to have to look up for distance, I'm happier actually changing glasses when I need to do so.

(And if I can I'm going to insist on glass lenses next time, the plastic ones are lighter but I get chromatic aberration near the edges, and as I use peripheral vision a lot it's annoying.)

January 2014


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