One question I’m frequently asked concerning binoculars is about eye relief: “Can I use binoculars with my glasses?” or “Tell me what eye relief is.”
Some people think, after doing some quick research, that binoculars with long eye relief are the best; this is not true.
I used to be very near-sighted and wore glasses for many years. About ten years ago, I had Lasik surgery. Since then, I have been living without prescription glasses.
So, I know how people with and without glasses feel when they use binoculars. Eye relief can be a crucial factor in how comfortable binoculars are to use.
In this post, I will explain about eye relief and how much is best for you.
About eye relief
First, have the eye-cups lightly touch your face. Next, slowly move the binoculars away from you until you find the point where you cannot see a full image anymore.
This point is called the “eyepoint.” “Eye relief” is the distance between the ocular lenses and the eyepoint.
If your eyes are off the eyepoint, you will only see a partial image or no image at all.
For eyeglass wearers, long eye relief is the solution.
Eye relief is important, particularly for eyeglass wearers, because their eyes will be further from the ocular lenses. In other words, eyeglass wearers need binoculars with longer eye relief.
A 15mm eye relief is usually long enough for eyeglass wearers. Binoculars with a long eye relief enable eyeglass wearers to get a full field of view.
Please check whether the binoculars you buy have a long enough eye relief.
How much is the best eye relief for you?
When I wore glasses before my Lasik surgery, the reflection from my glasses was annoying and prevented me from seeing clearly.
Also, I couldn’t use some of the second-hand pairs I had bought on internet auctions, because their eye relief was too short. When I tried to use them without my glasses, I couldn’t focus on distant objects.
I had hoped that after my Lasik surgery, I’d be able to easily use all of my binoculars. Unfortunately, this was not the case with the pairs with long eye relief.
My new problem was the following.
Binoculars are most stable when using both hands and both eyecups are touching (see below).
However, if the eye relief is too long, you have to hold the binoculars away from your face, losing the support of the eyecups. Because of this, the shakiness of the image becomes greater.
So please understand that binoculars with long eye relief are not always the best choice even for eyeglass wearers.
When non-eyeglass wearers use binoculars with long eye relief, they probably need to adjust the eyecups. The eyecups should be fully extended to make up for the long eye relief.
Eye relief is the distance from the ocular lenses to the point where you can still see a full image.
It is essential to consider eye relief when buying binoculars, particularly for eyeglass wearers. The reason is that their eyes will be further from the ocular lenses with their glasses in-between.
For eyeglass wearers, long eye relief (over 15mm) is the solution. Some people are under the misconception that the longer the eye relief, the better.
You can use binoculars most comfortably and with the least shake when you hold the barrels with both hands and have the eyecups either touching your face or glasses. If the eye relief is too long for the eyecups, you’ll have to hold the binoculars away from your face, which causes shake.