DIY Glasses

Posted: 10/14/2019 1:11:51 AM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

It's way past time for a visit to the ophthalmologist as I'm squinting like Popeye when at the PC.  Got inspired by this link off Hacker News:

https://www.eidel.io/2019/04/24/making-my-own-glasses/

Looked up my own prescription (nearsighted around -3.5 spherical with a bit of axial) and just ordered this 158 piece lens kit which covers that range as well as the more extensive/expensive kits:

https://www.ebay.com/itm/262534593736

The metal lens rims look like they give a larger diameter lens than the plastic holders, and the lenses themselves are supposedly glass rather than plastic. 

Many of the comments in that post ring true, you're sitting with a somewhat disinterested person for a few minutes who is supposed to be helping you determine your prescription for the next several years at least, and it doesn't always go well.  "Is this better or worse?" - I dunno, it's different?  Since my teens I've been over and under corrected several times, and last time the ophthalmologist swapped my wife's eye corrections (OMG).  Time to take this bull by the horns by sticking some lenses in a test frame, playing around with things a bit, and give them an extended spin.  $39 glasses (https://www.39dollarglasses.com/) doesn't care where the prescription comes from.

Probably the best place to get a prescription is from an unaffiliated ophthalmologist, rather than an optometrist or a glasses retailer, as they have no special interest in what you do with it, and they can take a peek at your retinas and floaters and whatnot.  And them being a medical specialist, you can often get it covered by your HMO or whatever.  The glasses biz is a total racket.

To be continued...

Posted: 10/14/2019 1:32:36 AM
oldtemecula

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014


It would be awesome to see more clearly, you should also get your hearing checked.

Christopher


Posted: 10/14/2019 6:04:31 PM
ILYA

From: Theremin Motherland

Joined: 11/13/2005

dewster,
I have long suspected that you have vision problems

Posted: 10/15/2019 1:47:07 AM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

"I have long suspected that you have vision problems"  - ILYA

Ha ha!  It took hard reality (and gentle prodding from you) to make me "see" the error of my ways!   Thanks!

(I believe a sufficiently linearized function here - it works quite well on the D-Lev anyway - is the root of the inverse of the frequency difference.)

Posted: 10/18/2019 8:20:29 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

Diopters

Lens kit came today and I've been playing with it some.  The trial frame is pretty crappy so I just ordered this metal one for $20 USD:

https://www.ebay.com/itm/303178984161

The trial frame also places the nearest lens rather far from my eye, which alters the way it changes the focus; the trial frame I just ordered has a position behind the bulk lens holder for the primary lens, which should address this situation.

Turns out the diopter measurement for your eye is just the inverse of the distance in cm at which things start going a bit blurry.  You can measure this right now by looking at some text on your monitor and moving away from it (if you are nearsighted) using a tape measure from the monitor to your eye.  There are simple ways to measure astigmatism (cylinder & axis) as well without any special tools, which was a surprise to me.  This whole field is remarkably hackable.

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