When all else fails I get out the digital microscope... I really don't need glasses anymore for distance except for my astigmatism. Been nearsighted since preteen, needed bifocals for close work in my 30's and then my nearsightedness went away in my late 50s. Passed my driver's license renewal exam without glasses the last couple of times. Was just using drugstore reading glasses but they weren't cutting it looking back and forth from the bench to the computer.

 

I was nearsighted and started wearing glasses when I was 10. Shifted to contacts while in college, but further eye changes necessitated bifocals.
Then when I got into my sixties, my eyesight worsened. Cataracts. I received operations in both eyes. I chose a mid-range focal distance since I was on a computer monitor 10-12 hours/day. Bad decision. After the operations, I lost my job and decided to retire.
I don’t need readers, but will wear them because I read a lot and my eyes get tired. I don’t need glasses to drive, but always wear them for safety. I could go back to bifocals, but they were awkward. Don’t feel like learning to wear them again.
So, your eyes change over your lifetime. Just go with the flow.

 

Hmm, I don't feel like getting into prescription anything if I can avoid it. In my teens I'd get an eye exam and stronger glasses just about every year, I didn't like where that was headed. Anybody experiment with negative diopter glasses? Wearing readers so much (~8 hours/day) my eyes have gotten used to them, I can see to walk with them on. Negative diopter glasses train your eyes back to other way. I've heard of them, never tried them. Good Aliexpress project maybe.

Looked it up on there and negative diopter glasses came up as myopia https://en.wikipedia.org/wiki/Near-sightedness glasses so that's sort of back where I started for a different reason. I might try a pair for under $10 https://www.aliexpress.com/item/330...earchweb0_0,searchweb201602_,searchweb201603_

I haven't bothered to try a digital microscope really, I have a few cameras that would work.

Back to, well, I guess it was a different thread. I want to run remote microphones, and I'm looking at preamp and emitter follower circuits. And I have a couple hundred feet of CAT5 cable leftover from years ago. It has an impedance of 100 ohms https://en.wikipedia.org/wiki/Category_5_cable it's 4 twisted pairs but no shielding. If I use a few conductors for power and make a pair of preamps with emitter follower outputs I can probably feed audio back on a couple other pairs. Use DB-9 connectors which I've got. Too cold to do much outside now until spring anyway.

 

Here is one of my books was it this?
kv

 

No, sorry, this one from 1971.