Thanks for sharing the problem. I also, am near sighted; i used to be able to read the fine print around Presidents on bills, as well as the signature "line" on checks - easily. No more..getting to where placing a 0603 properly is near impossible.
I tried it. Didn't like it. It's still better than the alternative.
-- Virg Wall, P.E.
The parts keep getting smaller. 0402, 0201, chip-scale stuff. You need optics. I use my Mantis for the small stuff. It's great to work under.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
I find I'm even using the Mantis for big stuff, even putting banana plugs on wires. The optics are great.
A bench vise will fit under the Mantis, as will your hands and some tools and a soldering iron.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Opthalmalogists call "two eyes, each with different focal lengths 'monovision'." You can ask for it and they'll do it.
I'm naturally that way. I like it, but some people find it intolerable--they can't fuse images from the two eyes; they get double- vision. It's a brain-thing. Some adapt, others never do.
So, the standard is to try it out first with contacts that simulate the target Rx.
The multi-focal lenses I looked at ten years ago just superimposed several images. You picked out the one in focus. Not my cup of tea.
-- Cheers, James Arthur
Ergonomically, my big Mantis works well with a Panavise with the jaws bent over sideways, but not as well with them upright.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 USA +1 845 480 2058 hobbs at electrooptical dot net http://electrooptical.net
I can think of worse ways to go. And once you're dead, you won't care that you died.
Sylvia.
Depth perception has to go out the window, too.
I certainly would simulate it before taking that big of a leap. I wouldn't do contacts, though. I just can't grok sticking something in my eye intentionally.
That would be pretty bad in low light, no? I can see real problems driving at night. Ick!
ocal-length lenses, maybe with astig correction. I've always been nearsight ed, which suits me fine, since I read a lot, compute a lot, and work with t iny parts on PC boards. I can wear glasses to drive or ski or whatever. So, what should the focal lengths be? I've noticed that two eyes have a lot be tter resolution than one, even if one isn't well focussed. Brains integrate the images somehow. Some people go for one eye close-focussed, and one at distance, so they don't use glasses at all, but I have another idea: Focus one eye really close, like 10" maybe, and the other at computer distance, 2
0" maybe. Ideally, that will give me good resolution from, say, 8 to 24 inc hes. Something like this:Worn glasses since a kid for near sightedness. Do a lot of reading and clo se work without the glasses. Focus distance was 8-9? until cataract sur gery moved it out to normal reading distance. Did not want to loose the no glasses close up work ability. Just see better close without the effects o f optics. So used to wearing variable glasses that it is not an issue to c ontinue doing so. Doctor had no problem setting the focus close, although when it was over she said she had only done it 2 or 3 times in 30 years. Could drive without glasses if need be in familiar areas, sometimes run aro und the house without them. Getting close to a year since surgery and hav e no regrets.
I got an extra pair of presciption glasses made optimised for close work
- a whole new world when I first put them on! Good for high DPI monitors too.
-- John Devereux
I'm not sure about that. Testing with standard 3-d images, I had almost zero stereopsis, but I was able to develop it with just a few minutes' practice. OTOH, I've never been able to view those magic diagrams, the ones that appear if you defocus and gaze past them.
You have to use contacts. Brains rely on cross-correlating the images from both eyes to combine and fuse the two images. That doesn't work if the sizes are too different.
Unequal external lenses impose a magnification / minification differential, which is enough to give lots of people double-vision (or greatly distressing eyestrain as their eyeballs fight and servo, trying to sort out the conflicting feedbacks) all by itself. Different people have different tolerances.
Simple lenses introduce other distortions (like 'prism') which distort (warp and translate) images differently depending on angle-of- incidence, position on the lens, and Rx. Having external lenses that are too different can make someone very uncomfortable. To imagine the distress, imagine one eye looking through a circus mirror.
.Yep. Superimposing a couple of fuzzy / foggy images on top of a clear one sounded like a great way to waste scarce photons at night.
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Donegan's Optivisor's binocular magnifying lens head set is wonderful too. Their lenses incorporate prism, which lets your eyes point straight ahead and relax, as opposed to tiring, continuous convergence during close work.
-- Cheers, James Arthur
impossible.
Ya, I've been using them for 30 years. The problem with them is the short focal distance. I have searched for magnifying glasses that have about a 12" to 18 " focal length. They are out there but for something decent it's around $200 and I haven't pulled the trigger. Someday. If anyone has some they really like please post the brand and model. Mikek
I've posted these glasses before, but some may not have seen it.
Mikek
I have two pair of "clics" reading glasses...
One pair optimized for "book distance", and one pair optimized at arm's length for my monitor. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
rk
rs
ikek
Optivisors have replaceable lens plates rated in diopters.
DA-3 = 3 diopters, focal length = 1/(3 diopters) = 1/3rd of a meter =
33 cm.-- Cheers, James Arthur
Just saw the doctor. We're going for plain lenses, left eye 10", right eye 22", in January. I'll let you know how it works.
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
I use a relatively weak reading correction (+0.75 dioptre). My normal lab glasses are bifocals, +0.75 / +2.50. Decent frames, AR coated, $40 from Zenni Optical. I just went to the eye doctor for the first time in
25 years--all was OK, or at least as OK as 53-year-old eyes get.For most of my life, I've had really first-class eyesight, so it's a bit humbling not to be able to read without glasses. Good for my soul, of course--it's always useful to remember that if we live long enough, every single thing on Earth that we've ever cared about will be taken from us. (That clarifies a lot of issues.)
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 USA +1 845 480 2058 hobbs at electrooptical dot net http://electrooptical.net
impossible.
Old age is defined by stiffness... everything, including your eyes, gets stiff and unpliable, except for that part you wish to be stiff
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
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