I'm pretty short-sighted, about -8 dioptres, both eyes much the same. This can be handy for close work, but only monocular because I can't maintain the convergence at this distance for more than a few seconds.
So I need a pair of glasses with no magnification - or maybe a small amount - but crucially with prisms to converge my focal points.
Is there a non-custom solution which isn't too expensive?
Cheers
-- Syd
DIY Cast clear acrylic in a prism mould made out of microscope slides?
-- Regards, Martin Brown
I buy prescription prism glasses for my wife from Zenni for about $40. My glasses, with a nice frame but a simpler prescription, cost $22.
I make up my own prescription, two different negatives and one astigmatism, but I don't know how to do prism. I do my own reading glasses, too. Zenni is great.
-- John Larkin Highland Technology, Inc picosecond timing laser drivers and controllers jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
One approach would be two sets of specs, negative and positive, with very different interpupillary distances. you can get some to play with from Zenni Optical for $8 per pair.
Cheers
Phil Hobbs
Interesting idea. I'll try with my existing -8 specs, a couple of loupes and some Blu-tack, and hope no-one is watching.
Cheers
-- Syd
Maybe some eye muscle exercises would be useful, isn't maintaining convergence mainly a function of the ability to stay cross-eyed, ie using muscles or nerves in an uncommon way, so it should get easier if done more.
cheers, Jamie
You could get a large thin lens, and cut left-eye/right-eye lenses from off-axis regions. Fitting the lenses to a frame, though...
I think some of the commercial flip-down lens magnifiers are prism types.
Optivisor lenses have both magnification and prismatic correction. I don't think a zero magnification lens option is available. The table of magnification/focal length on their web site may give some idea of the "comfortable" viewing distance provided by this convergence.
You could contact them to confirm this.
-- Paul Hovnanian mailto:Paul@Hovnanian.com ------------------------------------------------------------------ Life is like a buffet. Its not very good but there's plenty of it.
Prism is a standard part of prescriptions, so this can be ordered in eyeglasses. Zenni Optical in China costs about $40 per pair, so one can afford a few tries to get it right.
They have a US presence:
Joe Gwinn
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