• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Eye relief for glasses??? (1 Viewer)

N

Nickolas

Member
Hi All,

I've recently found that I need glasses for astigmatism and am curious how much eye relief is usually needed. I tried my binoculars (supposed to be 18mm eye relief) with my sun glasses and I could not see the full FOV. I'm thinking the sun glasses must have something to do with it and when I purchase glasses I'll get ones that sit closer to my eye.

But on average how much eye relief is needed?

Thanks for any imput.

Nick
 
Nickolas said:
Hi All,

I've recently found that I need glasses for astigmatism and am curious how much eye relief is usually needed. I tried my binoculars (supposed to be 18mm eye relief) with my sun glasses and I could not see the full FOV. I'm thinking the sun glasses must have something to do with it and when I purchase glasses I'll get ones that sit closer to my eye.

But on average how much eye relief is needed?

Thanks for any imput.

Nick
Click to expand...

Nick,

I have often seen 15mm quoted as "adequate for eyeglass wearers." As you have found, that number can be a bit optimistic. I previously had larger glass that sat farther from my face, and they required about 19mm of eye relief. I now have a smaller pair that sits closer to my face, and I can get away with 15mm. If I add my clip-on sunglasses, however, I can not see the entire field with 15mm of eye relief.

To complicate matters, manufacturers don't seem extremely consistant in how they measure eye relief. If it is from the eye lens, and the lens is rather recessed because of the design, the number can be misleading.

I think the only way to figure out if a particular pair works for you is to try them. It sounds like you might want to start with those claiming about 20mm of eye relief. With good, adjustable eye cups, it is easy to adjust them if you actually need less. If you have too little, you are stuck with a restricted field or with taking your glasses off.

Clear skies, Alan
 
The amount of eye relief that you will need depends on how closely your glasses fit to your eyes AND how closely your bino oculars fit to your glasses. In general, binos with smaller diameter oculars do not need as much eye relief as those with larger oculars (because they fit more closely against the glasses). For myself, I have binos with as little as 13 mm eye relief through which I can see the whole field, and others that supposedly have 17 mm that do not have enough. I prefer 16-20 mm. Some of the variation has to do with how different manufacturers measure eye-relief, but much has to do with this issue of fit to my glasses.

Until you have figured out what combinations of factors work for you, the advice to try before you buy is solid. Incidentally, make sure you test for adequate eye relief under conditions of BRIGHT LIGHTING! It seems that when you are pushing the limits of a binos' eye-relief, the view is more constricted when one's pupil is contracted.
--AP
 
Make sure to check the eye relief of binos personally, or at least purchase them somewhere where you can return them. Manufacturers seem to measure eye relief differently -- some from the lens, some from the rim of the eyecup. The measurement from the rim of the eyecup is what some call "usable eye relief".

I have binos with a little more eye relief than I need -- especially under certain lighting conditions...I get some blackout if I don't hold the binos to my galsses perfectly. But my bins have eyecups that adjust with a few stops from all the way out to all the way in. The stop that is just before all the way out is often perfect for me. I would look for binos that have that sort of adjuctability.

15-17mm seems to work for me with my glasses. Usually sunglasses protrude farther from the face than regular eyeglasses.
 
Celestron Regal LX 8x42 has 19-20 mm eye relief, costs $450 or less, and is very well built. The eyecups are built for eyeglass wearers - they have a wide flat rim. Optically and mechanically excellent binoculars, with excellent resolution, good contrast, flat views almost free of distortion. Give them a try.
I gave my pair to my mother in law (i love her!) and she is birding happily ever since.
 
Thanks for the advice all.

It's too bad that there isn't any magic number for eye relief because there aren't many binocular places nearby, so I'll have to get a hold of some and try them and send them back if they aren't right for me. I guess eye relief measurements are somewhat like pants sizes, I've got a 40" waist, but I always buy pants cut large so that I can fit into a 38. Oh well.
 
Nickolas said:
Hi All,

I've recently found that I need glasses for astigmatism and am curious how much eye relief is usually needed. I tried my binoculars (supposed to be 18mm eye relief) with my sun glasses and I could not see the full FOV. I'm thinking the sun glasses must have something to do with it and when I purchase glasses I'll get ones that sit closer to my eye.

But on average how much eye relief is needed?

Thanks for any imput.

Nick
Click to expand...
It entirely depends upon the distance between the lens and your eye. I find the new flexi-frames the best as these seem to sit near to the eye and can be pressed comfortably against the binocular without a problem.

I would say 19-21mm is a real minimum, but I know many get away with less. The only bins I have been able to use with utter ease are the Nikon Sporters 8x36.
 
Nickolas,

I wear eyeglasses and have discovered two things:

1: I need more eye-relief than the most other users.
2: The USABLE eye-relief isn't the same as the stated.

The eye-relief a person needs depends on as well the shape of the face and thickness of the glass. This is very individual.
At some binoculars the ocular lens is deeply recessed in the ocular which means that you cannot make use of nearly the stated eye-relief.

Therefore you have to try before you by. I know several examples of binoculars who have stated the same eye-relief but it isn't the same in practice. Some binoculars have stated 18mm and is more than adequate for me, other with stated 20mm isn't.

In general, a binocular should have a stated eye-relief of 17mm or more to be adequate for me.

Try before you by!

Regards, Patric
 
Last edited:
Swedpat said:
The eye-relief a person needs depends on as well the shape of the face and thickness of the glass. This is very individual.
Click to expand...

...and the type of eyeglasses. You can choose a frame that allows the lenses to sit closer to your eyes. John Lennon type of eyeglasses, with small round lenses work best.
 
Warning! This thread is more than 16 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Similar threads

A
Usable Eye Relief (spartan method)
Replies
9
Views
528
Patudo
P
R
Binoculars and glasses/contact lenses
Replies
6
Views
866
ArchStanton
A
S
The topic of eye relief. What is it actually?
Replies
12
Views
998
WJC
WJC
B
Which monocular as a substitute for binoculars...?
2 3
Replies
41
Views
2K
wm.wragg
W
A
Looking for long eye relief binoculars
2
Replies
25
Views
4K
jring
J

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)
Back
Top