18-03-2012, 09:15 AM
(This post was last modified: 18-03-2012, 09:49 AM by Radio Fixer.)
When I type these threads straight in I dont give my self time to insure that all is correct and in context. Here I have forgotten to say that the small man, Joe at Smart Vision, is not an optician but a maker of glasses. So he is not set up to do the eye test but can check magnifications etc with add on lenses.
I checked up on the latest vari focals he made me and they were £122.
I started like you Alan... a pair of driving and a pair of reading and it worked fine. To me a single lens must be the easiest to make with no distortions... Then from there must be Bi-focals.
Vari's are probably more difficult to get right and I doubt they could do it without computers, in desgin and manufacture. I think, how well they work for you, is also dependent on how 'strong' you need them. The more mag you need I reckon makes for more distortions. In cameras its always at the edges that defects show up, more so with lenses for wide angle and telephoto, and I think the same with glasses.
If each eye needs similar mag adjustment amd other parameters like 'spherical' come out the similar then low cost super market specs, for the computer and even reading, work quite well for me. Its certainly handy having a few pairs around in different places to save walking up stairs again.
I asked Joe about having incorrect glasses and he said for short period use it wont do your eyes any harm. It will make it more tiring though for any duration.
For me vari's are the workhorse glasses, the ones I carry with me all the time, they can do everything. But I need, either because I'm very particular (well I have been a keen photographer for many years) a separate pair of readers and intermediates for the PC.
I couldnt use the vari's for the PC, as David does or read with them for long periods (or I chose not to).
I had hoped that the new Desktops would combine intermediates and readers into one pair of glasses but that isnt going to be the case. Good though they are, and useful for holidays and the like they are not as aberation free as separates.
Gary
I checked up on the latest vari focals he made me and they were £122.
I started like you Alan... a pair of driving and a pair of reading and it worked fine. To me a single lens must be the easiest to make with no distortions... Then from there must be Bi-focals.
Vari's are probably more difficult to get right and I doubt they could do it without computers, in desgin and manufacture. I think, how well they work for you, is also dependent on how 'strong' you need them. The more mag you need I reckon makes for more distortions. In cameras its always at the edges that defects show up, more so with lenses for wide angle and telephoto, and I think the same with glasses.
If each eye needs similar mag adjustment amd other parameters like 'spherical' come out the similar then low cost super market specs, for the computer and even reading, work quite well for me. Its certainly handy having a few pairs around in different places to save walking up stairs again.
I asked Joe about having incorrect glasses and he said for short period use it wont do your eyes any harm. It will make it more tiring though for any duration.
For me vari's are the workhorse glasses, the ones I carry with me all the time, they can do everything. But I need, either because I'm very particular (well I have been a keen photographer for many years) a separate pair of readers and intermediates for the PC.
I couldnt use the vari's for the PC, as David does or read with them for long periods (or I chose not to).
I had hoped that the new Desktops would combine intermediates and readers into one pair of glasses but that isnt going to be the case. Good though they are, and useful for holidays and the like they are not as aberation free as separates.
Gary
