Nikon Monarch Binoculars: Replacing the Eye Cup

Don't leave home without your binos.
Don’t leave home without your binos.

A couple of years ago, I damaged the right eye cup of my beloved Nikon Monarch birding binoculars. Ever since, I have been unable to adjust between naked-eye viewing (eyecup extended) and eyeglass viewing (eyecup retracted.) It was a pain in the butt—I switch between contacts and glasses all the time.

Finally I got tired of procrastinating about it and decided to fix it, and I discovered that my usual resources for repairing these things were sorely lacking. There were no online guides for how to do it—just other people out there with the same problem: a broken eye cup. There were no spare parts for sale on ebay or Amazon or online camera stores or anywhere else. I was stuck.

Then I decided to kick it old-school and contact the manufacturer myself. Bingo. An email to Nikon Canada got me an email back within a few hours. The guy who wrote was actually a parts specialist, not a customer service rep. He knew what I needed and said he could ship it right away. The only strange thing was that he asked me to email him my credit card info. Remember this is a parts guy, not a sales person. I emailed him back and said I didn’t want to share my credit card via email; was there a link to an online secure form? He said no, but I could call him up and we could do it over the phone. That’s what I did.

It was ten dollars for two eye cup units, plus fifteen bucks shipping via Purolator. You might be able to negotiate another form of shipment, I don’t know. But the package arrived the next day and I got to work. There were no instructions in the box at all, and that’s why I’m writing this—so you can learn from my fail, so to speak.

Left to right: rubber eye ring, screw base, twisty bit.
Left to right: rubber eye ring, screw base, twisty bit.

The first thing you’ll notice is that there are three pieces: the rubber eye ring, the screw-on base, and the twisty extending bit. If you’re like me, the part that got damaged was the screw base; it’s a bit thin and once it breaks you’ve got no firm attachment between eyecup and lens. Remove your old screw base by unscrewing it counter-intuitively, the opposite of rightey-tightey lefty-loosey.

Lefty-tightey. I know, right?
Lefty-tightey. I know, right?

Now your first instinct is going to be to screw on a new base right away. That was my mistake. Once you do that, there is no logical way on earth you can attach the next piece, the twisty extending bit. It’ll make you a little bit insane. But somebody far more clever than I suggested I pull that screw base off again. See? You need to push the twisty bit over the screw base before the screw base goes on. Brilliant, isn’t it?

It will extend into place and stop.
It will extend into place and stop.

Now you screw on the base, again counter-intuitively.

There you have it.
There you have it.

Now all that’s left is to attach is the rubber eye ring. I noticed when I took off the old ring that it had been fixed on with a bit of glue. I haven’t glued my new one on, and so far I have no problems with it slipping off. But you could use a bit of epoxy and I’m sure it would work fine.

You're good to go.
You’re good to go.

The only issue now is that the new eye cup is considerably looser than the old one; it slides a bit too easily between the extended and the retracted positions. It’s not a big deal, but if you have any ideas how I can fix that, I’d love to hear it in the comments section below. EDIT Feb 2014: see Don’s comment below. There is a very small ball bearing that fits into a fairly obvious spot on the inside of the ring. It would be very easy to lose this piece in the process, which I did.

Good luck.


  1. Hey happen the same to me, but worse im in México so no Replacements and try the canon mail and did not work hehe thanks for the video

  2. Hola Jairo- maybe Nikon Mexico can help you-

    Otherwise try the Canadian office ( and see if they can help you.



  3. If you have your old eye cups , there should be 3 little rubber tabs about 1/4″ long and those tabs belong in the 3 groves on the rotating cup . That’s what causes the friction so the cups are stiff to rotate in and out along the rim line . I just ordered the cups for mine but they are different than what I have and I am still trying to return them to Nikon or order different cups.. I have 8×42 Monarch ATB from 2008 ..Did yours come with ballbearings in the 3 holes or screws ??

    tnx Don

  4. Hi Don and thanks so much for your comment. I see now that there were tiny ball bearings in place that provide the friction to click the cup as it slides in or out. I don’t know if there were ball bearings in my replacement kit that I missed, or if I should have transferred them from old to new. At any rate, they appear to be lost now. But you’ve solved the mystery and for that I thank you.

  5. Update- Rob over at has an entry that appears to feature updated parts from Nikon. I’m curious to see if that’s a New Zealand thing or if it’s worldwide. I guess I’ll find out soon: I’ve broken the eye ring again. Grrr. Anyway check it out:

  6. Sarah Termondt

    Thanks! Just contacted the parts department because the same thing happened to me. I appreciate your help 🙂

  7. Nikon’s so awesome, especially in customer support. I’m using many binoculars of Nikon for different purposes, include a Monarch 5 8×42, always satisfied with them in support!

  8. Kind of a newbie here. Did you go to the Canada parts department because that’s where you’re located, or because they weren’t available in the U.S.? I’m in the States, and just want to get the parts with as little bother as possible.

    • Hi- yes, I went through the Canadian shop because of my location here. Try the US parts people first, I would suggest.

  9. Thanks for the instructions. My eye cup with the ball bearing poped off and I was lucky enough to retrieve it. It is tiny and re-installing it most difficult. After several attempts the way that worked was to place the bearing in the circular indentation on the lens holder which you have placed in a level position with the indentation up. Then slip the cap on lining up the notched grove in the eye cup with the bearing which provides 3 clicks of adjustment by notches in the inside grove of the cup.

  10. Do you have a part number for eye reliefs? Nikon told me I have to send binoculars in for service.

  11. Thank you for the information on your post. I just called Nikon USA to order the eyepiece for my Monarcchs and they told me I would need to ship my binoculars to them for repair; they would not send me the eyepiece. After relying the info. receieved from your post, they said to try and call Canada!!! So much for Nikon USA being helpful.

    • Yvonne- I’m sorry to hear that. I don’t know why it should be so difficult. Those eye cups are the Achilles heel of an otherwise great product. I have managed to damage both eyecups (again) on my binos and am getting tired of fixing them. Time to find another brand.

  12. this was a good read. your hyperlink to the Nikon Canada email is slightly wrong. it’s and not . i was able to get ahold of them and they sell the parts direct for $10 each plus $15 shipping. Nikon USA says it’s a service issue only and will not sell the parts. that doesnt make sense, really. But I guess it does, when I really think about it…. right?

    • Don Enright

      Thanks very much for the correction- I will fix it. Glad you got the parts. I now have two eyecups to fix… again. Getting tired of this faulty part.

  13. Cesar Levys

    Don thanks for your video.
    I live in Florida and have some 16×50 Action Ex
    where I can buy eye cup?
    I appreciate the help,
    César Levys

  14. Very useful post.

  15. Thanks for this Don most helpful

  16. Linda Enger

    Hi Don,
    Thanks so much for this post. I have the exact same pair of binos and the left eye cup broke. I thought I would have to send the binos away to be repaired when I came upon your posting. This is most helpful indeed!
    Thanks again,

  17. So many years after your very helpful post, I’m contacting both Nikon USA and CA in hopes that I can get this part for my pre-2000 Monarchs.
    Thanks so much, and wish me luck!

  18. same problem with my monarch M511. if anyone can get parts replaced please post here.

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