Eyeglasses for birding (1 Viewer)

A dedicated pair of eyeglasses for birding is a good idea as it can solve quite a few problems.

Some requirements based on my experience:

• round if possible as they fog less with air gaps where you don't need the glass (well, plastic).
• close tight fit to the eyes (to minimize ER)
• high index to make the lens thinner to minimize ER (even though it generates more transverse CA at the edges). Makes more of a difference if you have a strong prescription. CR39 is optically a better choice (and cheaper too).
• strong frame that seats well on your nose so you can press on it without it digging into you or flexing or popping a lens. I find a rimless frame a bad choice both from comfort and the need to make the lenses thicker to carry the load (especially with CR39).
• with anti-reflective coating. You don't want to loose 4% just in front of the eyes now do you after obsessing over your bins transmission.

You can even use regular lined bifocals if you keep the line out of the ocular i.e. you place the line much lower than usual (aligned with the lower lid) but you have to be prepared to make some measurements to get the placement right (a digital camera and a ruler works well!). You need to explain to the eyeglasses maker what you are doing too.

The are quite a few internet optics companies that can turn out reasonable glasses at reasonable prices for single vision or bifocal use(but avoid progressive lenses unless you really want to learn about ophthalmic optics ... the fitting is critical).

I'm curious how others deal with wearing eyeglasses and using bins. Do you have a dedicated pair of glasses for use with bins?

Ophthalmic optics! A whole new field of optics to obsess about

Well, yes, obsess. Is it the objective lens, or is it the eyepiece? At least we don't need those troublesome, high math requiring prisms.

Kevin Purcell said:

I'm curious how others deal with wearing eyeglasses and using bins. Do you have a dedicated pair of glasses for use with bins?

Ophthalmic optics! A whole new field of optics to obsess about

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Don´t tell the marketing guys, they´ll start producing "high-end" birding spectacles and have us all suckered again.

I have a pair of dedicated birding specs, gold wire-framed, round and tight fit as you describe. I bought the frames second-hand in Camden Market, London, for six pounds sterling, about 1985... they´re classic British National Health Service issue, from the fifties or sixties. They do just the job. I wouldn´t like to lose them because I notice the current fashion in specs is for small rectangular frames, round ones seem impossible to get.

Why bother with spectacles, this site seems to have the answer and at a reasonable cost.
http://www.lasikathome.com/

No more wiping the lenses in the rain, no slipping at the wrong moment.

Thanks, Keith, that's the funniest thing I've seen today.

I congratulate Sancho on his eyewear (and taste in daft humor on another thread).

And to prove that I'm an ophthalmic optics geek I wore a pair of those NHS 422CJ glasses through my twenties. They've become rather collectible (mostly because they're built to last!).

Of the internet optical firms one (which I'm just about to order from) that does round glasses is Zenni Optical.

http://zennioptical.com/

e.g. this one with 41 mm dia lenses and a wide bridge (which in an ideal world would be mounted a bit higher)

http://zennioptical.com/cart/product.php?productid=647&cat=16&page=1

What is the largest ocular you've measured on a bin? I my collection I think the largest I have is 23 or 24mm in diameter so a bifocal line has to be more than 12mm below the center of pupil when looking ahead. I suspect there can't be to many too much bigger than that.

Kevin Purcell said:

What is the largest ocular you've measured on a bin?

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I'm fairly certain the largest oculars in my binocular collection are 23 mm (Zeiss 7x42 Classic), but the Swarovski doubler has a recessed ocular that is ~25 mm, and scope eyepieces can be even larger.

As for glasses, I use the same glasses for birding that I always wear. They are a modified aviator style (cut down a bit, especially top to bottom dimension, so that they fit a bit closer than standard aviators) which I like for the very wide FOV and for the protection from branches and wind that they afford. I'm comfortable down to an honest 13 mm eye-relief. The frame is very sturdy/rigid (but the metal malleable, so they bend rather than break if subjected to trauma) with spring hinges. The lenses are glass for ultimate scratch resistance. My lenses are multicoated but I'm not sure I like it because to reap the benefits the lenses have to be kept very very clean, which I find somewhat difficult to manage. It is quite difficult to remove oil from multicoatings as compared to plain glass, and last time I checked it wasn't possible to get Lotutec or similar on a glass eyeglasses lens.

--AP

Hi Kevin, I have been thinking of ordering some glasses off Zennioptical. Would you please post what you think of the glasses.
Regards,Steve

I've not used these guys yet.

I have used a couple of other internet glasses outlets.

LBWeyewear just didn't seem to be able to get it right. First pair solidly and accurately made but omitted the AR coating plus their default for the bifocal line was a bit low (IMHO). Offered another pair for $20 shipped (a big discount) or 50% off the next order. Decided to go with rimless bifocals. Order arrive with no AR (again!). And a rather wavy cylinder on the right (less dominant eye). Complain. No response. Give up. Three weeks later eyeglasses arrive with AR but with worse cylinder cut on left eye (a ripple in it) and a little on the right eye too. Works OK for everyday use but you can see the loss of sharpness when you focus on it. These were rimless with CR39 lenses rather thicker than I was used to. So for < $100 I have three pairs of glasses: he original no AR and low bifocal that make a OK birding eyeglasses (lower bifocal and AR would be ideal!); a decent pair without AR and a mediocre pair with AR. I can't recommend them.

The other (my first) was a rimless set of single vision reading glasses with default higher index plastic from Goggles 4 U. They were inexpensive $30 or $35. Apart from a slightly wonky setting of the bridge (a little tilted) they are optically excellent and make excellent reading glasses. I would recommend them BUT their web site could use a lot of work. Each seperate color of a frame is a separate SKU. The site is difficult to navigate.

So I've been trying to decide on the next set. Zenni is going to be it as I want round glasses.

An excellent blog to follow this sort of stuff (and an associated Google Group) is GlassyEyes. He also recommends some places and they're pretty good.

http://glassyeyes.com
http://glassyeyes.blogspot.com/
http://groups.google.com/group/glassyeyes

The online eyeglasses makers all have the same business model. Order taking online in the US, Europe or Hong Kong and manufacturing in, usually, the PRC, Pakistan, UAE. This lead to some interesting effects in the early days: like custom made hemp/hessian bags with handwritten addresses coming from Pakistan and attracting the attention of the USPS (what could they contain terrorist materials (they're that dumb ...), drugs (OK, perhaps), eyeglasses (nah!)?). But today they're seem quite professional.

And the costs are reasonable given a wholesale CR39 lens pair sells for less than $1 at the factory (a lot less from some sources). They're cast from a excellent optical thermoplastic so once the molds are made their manufacturing cost for blanks is low. The maker will figure a cylinder (for astigmatism) on the back side of the black and then cut and grind it to fit the frame.

Quality varies but I think if you stick with the top contenders you'll do best.

Single vision is easiest to get right. Bifocals a bit more tricky (and you have to do the fitting youself which is easy once you know). Progressives are a possibility from the better ones but you have to self-educate to fit them properly and you need an accurate IPD measurement (to the 0.5mm if possible per eye).

There are also some good outfits (usually US or UK based) that will reglaze your current frames (replace lenses with new prescriptions). These guys often sell both generic lenses and brands a binocular user would recognize (Zeiss, Nikon, Pentax, etc).

Like buying bins a little research can help a lot. Start at this very useful wikipedia page (and read it's associated links!).

http://en.wikipedia.org/wiki/Corrective_lens

Know your RX and your measurements like minimum frame width and minimum temple length and particularly your IPD which a lot of opticians will fail to tell you because it's not part of the RX though you'll find it on glasses specifications if you've had glasses made. Costco I've heard will do your IPD measurement for free as a customer service.

Like I said, it's a whole other area of optics to obsess over

Good post Kevin!

But should they have open hinges or not?

Bob

Only the fashion conscious wear open hinge eyeglasses. The real birders wear porros. None of that carrying them around your neck nonsense.

Kevin Purcell said:

Only the fashion conscious wear open hinge eyeglasses. The real birders wear porros. None of that carrying them around your neck nonsense.

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:-O:-O:t:
LOL
Bob

Kevin, from the otehr thread, you are absolutely right, The glasses give me extra distortion with all binoculars. It is just that I never noticed it before. All the times I have used the glasses, I have been in a hurry to see a bird. Then I write down the bird info and take the glasses off. I was not there to test optics any of those times.

Let´s post photos of our birding specs! Here´s mine....on desk and attached to Sancho´s Royal Skull:

Very nice, Sancho. They're excellent frames. I'm really sorry I threw mine out (after I lost a nose pad ... I kept them for a couple of years too then threw them out then realized they were THE John Lennon glasses not just ones that looked like them!).

Thanks Kevin! Yeah, I like my specs. Next thing I must do is have that bonsai-birch removed from my left shoulder.

" Next thing I must do is have that bonsai-birch removed from my left shoulder"

Sancho, You're funny. I enjoy your posts.
Regards,Steve

mooreorless said:

Sancho, You're funny. I enjoy your posts.
Regards,Steve

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Very kind of you, Steve...but I don´t think I´ve ever made an original joke in my life....

Come on chaps, post photos of your birding specs!