Should I Wear My Glasses When Using Binoculars?
We have been asked this question a number of times just lately so we decided to write this article in answer. There are a number of reasons that require you to wear glasses and depending on what your eye issue is, you might need to keep them on while using binoculars.
Differences In Eyeglasses
There are some eye conditions that won’t require you to wear glasses whilst using binoculars, and some that will not allow you to use binoculars without them. Let’s look at some eye conditions and see wherever you’ll need to wear your glasses when using binoculars.
Farsightedness Or Nearsightedness
In most cases anyone that wears glasses for either of these conditions can remove their glasses while using binoculars. The binoculars can correct these issues using the diopter and focusing knob. However, you might have an issue if you were hunting over rough terrain, as you’d be constantly removing and replacing your glasses.
Plus there’s the question of where you would put your glasses in between walking etc. If you were bird watching the same problem arises, plus with the time it takes to change from glasses to binoculars, you could have missed the only possible sighting of that extremely rare bird you were looking for.
This condition causes a distorted image due to the light that enters your eyes not focusing on a common focal point. If you do suffer from this condition, you will need to wear your glasses while using binoculars. If this is the case we recommend binoculars with long eye relief.
Bifocal, Trifocal Or Varifocal Glasses
If you wear glasses with two, three or more lens powers on the same lens, you’ll probably be able to remove your glasses to use your binoculars. If there is a specific part of the lens that you need to see you might have to wear your glasses while using binoculars.
Progressive Lens Glasses
These glasses have various areas of different strength lenses that change smoothly over different areas of the lens. If you use this type of glasses, you will probably need to keep them on while using your binoculars.
Those of us that wear glasses can find it difficult to use binoculars because of the way binoculars are designed. The eye cups are designed to block light from entering so that the only light our eyes can see comes from the objective lens.
Wearing glasses whilst using some binoculars can cause extra light to enter via the ill fitting eye cups. If this is the case, the image you see will not be as clear or properly focused. To solve this problem, binocular manufacturers design certain pairs of binoculars with longer eye relief than is standard.
What Is Long Eye Relief?
Eye relief is the correct distance between your eye and the binocular lens to allow perfect viewing with a clear image. This is usually determined using the eye cups that cushion your face from the binoculars and support the correct distance for perfect viewing. The eye cups are usually adjustable to a certain degree either by folding or twisting them up or down (depending on the brand of binoculars you own).
Long Eye Relief
Binoculars with long eye relief have a greater distance between the lens and the user’s eyes before that sweet viewing spot is reached. That extra distance is called long eye relief. Many manufacturers don’t make it clear that their binoculars have long eye relief, all they usually put in the specs is the actual distance of the eye relief.
Any binoculars with an eye relief greater than 16mm is considered to have long eye relief. Many modern binoculars have an eye relief of 17, 18 and in some cases 21 mm eye relief. Having this extra distance will help to accommodate your glasses while using the binoculars.
The Hawke Frontier HD X 8 x42 binoculars are a great example of binoculars with long eye relief but with no reference in the description. All it says in the specs is 18mm eye relief, but as anything over 16mm is considered long eye relief, 18mm is definitely long eye relief.
Possible Problems Using Binoculars While Wearing Glasses
Some of the following points might apply to glasses wearers that keep their glasses on while using binoculars.
- Reduced Light
Wearing glasses can affect the amount of light entering your retina. This is due to the extra layer of glass and can be exaggerated if your glasses lack any coatings or have any UV filters.
- Scratched Glasses
If the lenses of your glasses have any slight scratches, it could diminish the quality of the light that can enter your eyes.
- Imprints On Glasses
The eye cups can leave an imprint on the lens of your glasses. This is a particular problem if your eye cups are made from rubber.
- Night Sky Blindness
To get the best from stargazing using binoculars you will find it’s best to not wear glasses as these will impinge on the image.
In a perfect world, you should remove your glasses when using binoculars, but if you have a condition that means you need to wear glasses constantly, there are ways to accommodate this. Look for binoculars that have long eye relief (greater than 16mm). If you’re looking for a good value for money pair of binoculars with 18mm eye relief, check out the Hawke Nature Trek 8×42 for less than £150.00.
Frequently Asked Questions
Whether you should wear glasses when looking through binoculars depends on what eye problems you suffer with. If your issue is long or short sightedness you can probably take your glasses off while using binoculars.
If the binoculars have been dropped or knocked they could be out of collimation. If this is the case they could cause you to develop eye strain and headaches. But generally, binoculars should not hurt your eyes.
In binoculars, eye relief is the distance between your eye and the lens of the eyepiece. Where the exit pupil is formed and you can see the clearest image with no black circles.
If you see double when using binoculars it is usually because the binoculars need collimation. If the collimation is out it is usually the result of the binoculars having been damaged, often by dropping.
The binoculars should not touch your eyes, the eye cups should touch your face but not your actual eyes.