a first

[cellio]

This morning at my ophthamologist's office, through the collection of lens parts that she used to mock up a new glasses prescription for me, I read a letter from the 20/30 line. I have never done that before. Woot! Yeah, office conditions are probably optimized compared to real life, but even if the raw numbers don't matter the deltas should. And yeah, it's only one letter, but it still passed a threshold. (If I understand correctly, this would mean a rating of 20/38 on that single test.)

Now if I can just find an optician to correctly make them for me. I had rotten luck with that last time around. (The guy I used before those guys was excellent -- but he retired, which is why I went to someone else.) Locals, any recommendations? I have a complicated, finicky prescription and complicated, finicky needs on things like the precise placement of the bifocals. I need someone skilled and detail-oriented who (1) is that scrupulous about what comes back from his lab and (2) can work with me on this. I recognize that this is a non-standard level of service for which one should expect to pay extra. (I would also like someone to advise me on frame shape to optimize my vision; most places want to optimize their bottom line or some sense of "fashion".)

Bonus points for proximity to either Squirrel Hill or South Side Works, because even if he is excellent I'll probably have to make a couple extra trips as part of this. My glasses just don't happen as one-shots. So running up to, say, Cranberry at lunch time (because places aren't open at 8:30AM) would be a challenge, though doable if absolutely necessary.

I don't know what most of this actually means, but:

OD: sphere +8.75, cylinder -2.00, axis 135, add power +3.75
OS: sphere +6.50, cylinder -2.50, axis 45, add power +3.75

Comments

[dr-zrfq.livejournal.com]

well, not sure how much of what I'm going to say is stuff you do know, but for what it's worth:

OD is right eye and OS is left. Sphere measures near/far sightedness, where + measurements are myopia. +6.50 is about on par with me, but as I understand it, the scale isn't strictly linear. Cylinder and axis measure astigmatism; cylinder readings with absolute values >= 2 (such as yours) are pretty severe IIRC. I'm not sure what the "add power" reading is for, as neither Alys nor I have one as part of our scrip (and I don't think Tony has one either).

The Add

[tc-tick.livejournal.com]

The add is the bifocal part.

Re: The Add

[tc-tick.livejournal.com]

OD +2.75 -2.00 075 add +6.00
OS +4.00 DS add +6.00

Re: The Add

[cellio]

What kind of (reading) focal distance do you get with add +6? I have the impression this is tweakable?

Re: The Add

[tc-tick.livejournal.com]

Short about 7".

The numbers BTW are in diopters == 1/focal length in meters. The higher the number, the shorter the focal length.

+6.00 = 16.67 cm or 6.56"
For a + number you can create a real image by holding the lens between a light source and a surface and moving the lens until it focuses the image of the source. Measure the distance and you can compute the diopters. Negative numbers are a bit harder as the image is "virtual" and best measured using another lens -- or a laser and measuring the exit angle.

Sphere = is for spherical as in the surface of a simple lens (+ is convex, - is concave.) Cylindrical is as if a cylinder was sectioned length wise and placed on the lens, and axis is the angle of the cylindrical axis. The cylinder creates distortion (like a fun house mirror) that hopefully corrects the distortion of the eye.

Terry is so astigmatic that he was 30 before they discovered his vision was correctable. He was having an eye exam and the dr. stopped while spinning the dial and Terry said STOP! The dr said you can't possibly see through that! His vision went from 20/80 to 20/30 in one fell swoop and he was able to get a drivers license.

[kyleri]

D for dexter and S for sinister...?

[cellio]

I assumed that and apparently we're right, but what I wouldn't have known if my eyes weren't of wildly different strengths is whether that's my left/right or observer left/right.

[kyleri]

Which, given how the terms are used in heraldry, would otherwise be an open question...

[baron-steffan.livejournal.com]

Precisely. Oculo dextro ("to the right eye"), oculo sinistro ("to the left eye"), and OU for oculo utro ("to both eyes").

[cellio]

Thanks. I've been told that I have severe astigmatism, BTW.