Can I wear my glasses when using binoculars?

We covered last month for the Birding with BINTEL Newsletter the basics around binocular sizing and what are some good options for bird watching in particular. 

The two main numbers, say 8x42, signify magnification and the diameter of the front lens in mm. As we talked about, these determine the magnification and size of the binoculars and while there isn't any hard and fast rules about what is the right one to use for birding, taking to the footy or nature viewing etc, they can be handy info when picking binoculars for your outdoor lifestyle and activities. 

There are a few other numbers that also worth knowing about but aren't as easy to spot. 

The first of these is eye relief and this is important for eyeglass wearers. 

Eye relief is the distance in mm from the glass surface of the binocular's eyepiece to where the image is formed. It's handy information because this the point where if you place your eye, you'll be able to see the entire image formed without vignetting - or chopping off the image a little bit from the sides. In other words, it's the best viewing distance where the binoculars produce their best image.

We find it's quite common when folks come in the store to try out good quality binoculars they push them right up against their face, possibly as they don't realise they don't have to so, or maybe from experience with more basic binoculars with hardly any eye relief.  You don't have to squish them into your eyes and you'll find they're designed to work a smidge away from them.

Why are binoculars with decent or long eye relief important?

There are a few reasons. First of all, binoculars with long eye relief mean that you don't need to position your eyes  close to the binoculars.  This means comfortable, relaxed viewing for extended periods of time.

Long eye relief also means they'd ideal eyeglass wearers.

Can I wear glasses when using binoculars?

Yes. In most cases you'll be able to wear glasses when using binoculars. 

How the binocular eyepiece lens lines up with your eyes when wearing glasses. Image via Nikon

The reasons why we wear glasses are many and varied and I'm no way in the slightest qualified to give any advice, so please take this all as a few suggestions only!

For many, glasses change the point where the lens in our eyes brings the image into a sharp focus. If you need glasses for long distance viewing due to conditions such as Myopia, also known as near-sightedness, your glasses are slightly re-positioning this point. This makes the views of distance objects sharp and clear, effectively replacing your glasses.

In these situations,  you might well find that you are able to use binoculars without your glasses.  There's also likely a range of other conditions that your optometrist such as astigmatism has treated you for, and prescribed glasses that have brought you vastly better vision. These conditions can't be corrected by simply refocussing binoculars slightly.  

Another consideration is many find that while they can use binoculars without their glasses, the hassle of taking them off and putting them back on again to look around can be a hassle so they simply leave their glasses on. 

When you need or prefer to keep your glasses on when observing through binoculars, the length of the eye relief becomes important. It's purely to do with how close physically you need to bring them to your face.

Binoculars with short eye relief will mean you'll need to bring them closer to your eyes to see the entire image, however you'll find that your glasses will get in the way! You'll still be able to focus the binoculars ok, however as they'll be a little bit further past the point where the image is formed, it will be cut off around the edges.

We'd suggest if you want to wear glasses when using binoculars, you aim for a pair with at least 16mm or 17mm of eye relief.  (You might get away with a bit less than this if your glasses are smaller and how they fit your face.)

Most binoculars will state eye relief as part of their specifications. If you pop into BINTEL we're always more than happy to show you a few pairs to work out which ones work best for you. 

Binocular eyecups - what are they?

Many binoculars have eyecups with fold away or in many cases, twist in and out. 

Some Nikon binoculars at BINTEL with their eyecups wound out.

Same pair of Nikon binoculars with the eyecups wound in via a simply twist

We get a lot of questions about binocular eyecups and what they do. They simply keep stray light from entering your field of view and provide a bit of shade. Eyecups DON'T change the optics of binoculars, except maybe offering a reminder that you don't to push them right up against your eyes. They often extend to roughly the distance of eye relief.

If you are going to wear glasses when using binoculars, make sure you wind the eyecups all the way in so they can be placed close to your glasses. 

When you visit BINTEL and ask to try out binoculars one of the things we'll ask is whether you use glasses for distance viewing. If you say yes, and you see our staff winding the binocular eyecups back in before handing them to you, this is the reason why.

Cheers,

Earl White 

BINTEL

2nd May 2025

PS: Next month we'll talk about the diopter setting on most binoculars. This is an adjustment to compensate the for slight difference many have in their left and right eyes, as well as a bit of info on field of view.