It's really not as silly as all that. Note that I carefully inserted "(for some at least)," suggesting that far sighted people can get along rather well without specs anyway. I'm one of them. Often the biggest problem is moderate astimatism correction. Furthermore, if I had to wear specs I'd rather take them off to look at a located bird with binoculars having my own prescription. This would be for several reasons:
1. Eyeglasses are often tinted, or even graded to darken in sunlight. This changes the color balance that may birders are concerned with. Where did the brightness and naturalness go that you paid $1500 to get?
2. Eyeglasses, like mine, are trifocals. This makes it somewhat difficult to align the exit pupil with the eye pupil depending on the size of the glasses and where the cut lines are located.
3. Eyeglasses rest on the nose, and vary in distance to the eye. Hence, a full FOV is often difficult to obtain, or one is forced to select from a limited set of binoculars with adequate eye relief. Prescription binocs would eliminate that and put everyone on the same footing, ... er, eyeing?
4. Eyeglasses allow more side-light to enter the eye and eyepiece, which is difficult to shield. The use of winged eyecups has limited utility at best.
5. Finally, pushing binoculars against eyeglasses is one of the more painful if not masochistic experiences a person with a long nose can experience. Ouch!
That's more than enough for me even if I were functionally blind without specs. Ah, which leads me to a final final point. Prescription binoculars probably would allow more elders with macular degeneration or peripheral vision loss to enjoy birding.
Elkcub
