“
Do I have to wear my glasses when I use binoculars?” Thanks to improvements in binocular design in terms of
eye relief, that’s a question I hear less often these days, but it is still a good question.
If you are simply nearsighted or far sighted, the answer to the above question is no, you don’t have to wear your glasses when you look through
binoculars, because you can simply use the binocular focuser to compensate for the correction needed. If you have astigmatism on the other hand, the answer is probably, yes, you should use your glasses with your binoculars because you cannot compensate for this optical deficiency by using the binocular focuser. As to how much image sharpness you lose, here, by not using your glasses just depends on how much astigmatism you have. In mild cases of astigmatism you probably won’t even notice the difference. I have a lot of astigmatism, though, so there IS a big difference.
I might add that there is some risk to your glasses by constantly taking them on and off when you use binoculars. It is all too easy to set your glasses down somewhere you shouldn’t. (I've even lost glasses doing this.) Then, too, for many binocular applications such as
birdwatching and hunting, that extra time it takes to remove your glasses can be a real penalty when you need to get into action in a hurry with the binoculars and, of course, there is also the extra movement involved that can alert birds and game to your presence.
The good news is that the majority of binoculars on the market today, especially
birding binoculars and
hunting binoculars, have enough eye relief to use with eyeglasses, so there is really no reason to take your glasses off when using binoculars in the first place.