Many people rely on glasses to be able to see normally. Those who suffer from severe ametropia usually have to wear their eyeglasses when using an optical instrument too. This can often lead to problems when using binoculars if you wear glasses.
Using Binoculars With Glasses
To see the projected image in its entirety when using binoculars, it is necessary that the eye is placed within a certain from the eyepiece. This is the “eye relief”, the place where the exit pupil of the binoculars meets the entry pupil of the eye. Only then will a complete image without shadows or constrictions be seen.
Because the eyeglasses create an additional distance between the eye and the eyepiece, the eye relief may be too short, i.e. the eyes of the observer are too far from the binoculars.
When do Eyeglass Wearer need Special Binoculars
Binoculars usually have diopter compensation, so one eyepiece can be finely focused, to compensate the eye different strength. The dioptric compensation for standard binoculars is usually around +/- 2 dioptric.
With only weak ametropia, where only the refractive power of the eye needs to be corrected, this diopter compensation may be is sufficient to compensate for the visual defect and you can use the binoculars without wearing your glasses.
Premium and high-end binocular models can have diopter compensation of up to +/- 8 diopters.
However, people with more complex restrictions, such as B. severe myopia, astigmatism or farsightedness are dependent on special binoculars that are suitable for use with glasses. These binoculars are characterized by long eye relief.
Binoculars for Eyeglass Wearers
Binoculars that are suitable for eyeglass wearers are fitted with special eyepieces that set the exit pupil further back than conventional lenses, thus the eye relief is longer. The purpose of this is that the glasses wearer can see the entire image without interference.
To achieve this, complex lens systems with 6 to 8 lenses are installed in an eyepiece. Because of this special feature, these binoculars with long eye relief, are significantly more expensive, but also much more comfortable to use.
Binoculars With Long Eye Relief
To use binoculars comfortably while wearing the glasses, the eye relief should be between 16 and 20 mm.
Nowadays, most binoculars, if you are not buying from the budget segment, have an eye relief that is long enough so that glasses wearers can also use the binoculars. Make sure to read the product description carefully.
Eyecups especially for Eyeglass Wearers
Many binoculars are equipped with eyecups. They are designed to prevent glare from disturbing stray light and bring the observer’s eye into the correct distance from the eyepiece so that the image of its entirety can be seen.
Eyecups are either made of plastic or rubber and must be retractable or need to be folded down so the eyeglass wearer can bring its eye near enough to the binoculars. Binoculars with non-adjustable eyecups may not be suitable for eyeglass wearers because of the above reasons.
What About wearing Contact Lenses
Wearers of contact lenses don’t have to worry about special binoculars. Just like normal-sighted people, contact lens wearers can use binoculars without problems.
For someone who is used to wearing contact lenses, there may soon be another option. Researchers have developed contact lenses that can zoom in on objects for a better view.
What are the best binoculars if you wear glasses?
When choosing binoculars for eyeglass wearers, you should make sure that the eye relief is between 16 to 20 mm. This should allow trouble-free use for most users.
You should also pay attention to the eyecups. These must be adjustable, ideally, they are of soft plastic or rubber and can be retracted or folded down.
Binoculars with low magnification (i.e. 8x) usually have a larger eye relief and also a larger exit pupil and allow the full field of view to be seen even with glasses.
The higher the magnification of the binoculars, the more complex and expensive the lens system must be so that the wearer of the glasses can use binoculars.