Question for eyeglass wearers (1 Viewer)

When using binoculars does it make any difference if the eyeglass lenses are progressive vs lenses that are only one field (distance)? Does either type work better than the other?

Hello Allen,

It never made a difference to me.

Stay safe,
Arthur :hi:

Me either

thisisallen said:

When using binoculars does it make any difference if the eyeglass lenses are progressive vs lenses that are only one field (distance)? Does either type work better than the other?

Click to expand...

YES, it does. HOWEVER, like so many things people love to worry about, you probably won't notice because of the dioptric accommodation of your eyes. :cat:

Bill

thisisallen said:

When using binoculars does it make any difference if the eyeglass lenses are progressive vs lenses that are only one field (distance)? Does either type work better than the other?

Click to expand...

In my case it made big difference and I could not use progressives. Also, I once had difficulty with a pair of bifocals so I went back and had them check the optical center placement. They were in different locations on each lens and not centered with my pupils. I was told "it doesn't make a difference." I made then readjust the setup to align the optical centers with my pupils in the correct position on the lens/frame. That was many years ago and since then I have never had a problem using my binocular.

PS
I noticed the optical center problem when I had to tilt my head upwards to see a sharp TV image.

thisisallen said:

When using binoculars does it make any difference if the eyeglass lenses are progressive vs lenses that are only one field (distance)? Does either type work better than the other?

Click to expand...

I had never thought about it, but since you mentioned it I focused a 10x bino on a distant target while viewing through the long-distance prescription part of my eyeglass lenses (I'm -0.5/0.75D myopic) and then through the mid-distance part, and I did have to adjust focus very slightly to keep the target image sharp. Since I'm more-or-less constantly adjusting focus while using binoculars, I guess I never noticed that some of the adjustment required was due to the two different prescription strengths.

John Frink said:

I had never thought about it, but since you mentioned it I focused a 10x bino on a distant target while viewing through the long-distance prescription part of my eyeglass lenses (I'm -0.5/0.75D myopic) and then through the mid-distance part, and I did have to adjust focus very slightly to keep the target image sharp. Since I'm more-or-less constantly adjusting focus while using binoculars, I guess I never noticed that some of the adjustment required was due to the two different prescription strengths.

Click to expand...

I think that’s what I notice as well. One of these days I’m going to try a pair of single field lenses (distance) to verify. I have sunglasses that are only distance. They may give an idea of focusing with and without progressive lenses.

I think it extremely likely that progressive lenses are going to degrade the image. You would have to be sure that an area almost as large as the eye lenses of the binoculars or scope is exclusively for distant vision. Otherwise part of the field of view is going to be compromised. In addition, the optical centres of the near vision area are going to be significantly narrower than your IPD because your eyes converge (squint) to view a near object. On my bifocals it's several millimeters less than my IPD.

Another advantage of bifocals is that any misalignment is immediately apparent. It would not surprise me if many users of progressives are trying to cope with misaligned lenses.

Personally, I think that progressives are a very overrated technology. My eye doctor always writes a near vision correction of +2,5 dioptres, which corresponds to a reading distance of 40 cm, but I always ask my optometrist for +2 dioptres (50 cm). This means that my worst case is +1 dioptre, i.e. objects 1 m distant with a slight loss of acuity and I can live with that.

Bifocals enable me to use the distant vision part of my glasses exclusively but if I set up my angled scope too high or try to view an object below the horizontal, the near vision section of my bifocals intrudes into the field of view and I find that rather disturbing.

John

I like to brace the eyecups against my eye sockets and so I alway take off my eyeglasses when using binos. With the 8x or 10x magnification of my binos the eyeglasses are not actually needed.

I wear progressives. I have no doubt that it has an effect on the view, but the image processing of our brain does a pretty good job of masking visual discontinuities. If one wears glasses, let alone progressives, the peripheral view is interrupted by the edge of the lens and the frame. Somehow we get over that pretty quickly. If one changes prescriptions or frames, it might take a day to adjust to a slightly different 'distortion' of the field, and then it becomes the new normal.

Fortunately, with binoculars, the field of view is severely limited, and the apparent field is also constrained, so the useful, coherent image is confined to whats visible within the field stop, in which case the 'distortions' added to one's default image appear to be solely the properties of the binocular itself.

I'm sure there are cases where either prescription, lens size, and/or eyepiece diameter, or possibly a huge AFOV, could impact the image through progressives in a more distracting fashion than what I've encountered so far.

Bill
(who is thankful there are binoculars that work for eyeglass wearers)