Doing without reading glasses

[pystab]

I need reading glasses to see close up, but my distance vision is fine. At the scope, I'd only use the glasses to read a star chart on a phone while star-hopping. (I'm visual only, without a goto mount.) However, the glasses-on-glasses-off hokey-cokey is very irritating, and I feel the glasses are vulnerable to getting crushed or scratched in the dark, even on a lanyard.

A related topic has come up on CloudyNights recently (https://www.cloudynights.com/topic/793604-presbyopia-and-contact-lenses/) where the prevailing opinion seems to be that people just put up with their glasses (or contact lenses - no thanks!) in various ways.

My current solution is to mount a cheap Fresnel lens with the phone on the scope:

The lens magnifies the phone's image and (more to the point) moves it further away, though it also superimposes its groove pattern and prismatic colours onto the image. The star diagonal and RACI finder (mounted on the tube rings) face the same way, so I only need to move my head from side to side. The lens and the phone holder come off for storage, while the metal bar and clip stay attached. I have yet to try the setup in dewy conditions.

I'd like to know what other solutions may exist for this problem!

[Starwatcher2001]

That's a cool solution. I use varifocals until I locate an object, then take them off to observe. As I tend to look at a single object for a good while it doesn't bother me as much. However, if there was a good solution I'd be all ears.

[bosun21]

I just keep a pair of my reading glasses on a cord around my neck. Solves the problem for me. I don’t like the thought of my phone screen next to my eyepiece. Dark adaptation and all that. As reading glasses are off the shelf (for me anyway) I don’t worry about them as they are very cheap to replace(what can happen to them). I’m just thankful that I don’t have to wear glasses observing.

Edited July 4, 2022 by bosun21
Spelling error

[ScouseSpaceCadet]

An interesting solution!

I'm a recent varifocal convert and luckily the new glasses are super light weight, so they don't slip or or fall off my head when pushed out the way at the eyepiece like previous pairs. I have been trying for ages to find flip up frames after reminding myself one of our members @cotterless45 uses a pair. Internet searches have been previously fruitless, but I've managed to find some pairs on Aliexpress. So I may pop into Specsavers with a picture and see what happens.

 

Edited July 3, 2022 by ScouseSpaceCadet

[JeremyS]

44 minutes ago, ScouseSpaceCadet said:

 

 

That’s exactly how my specs looked last when when I stepped on them having tripped over an abandoned scooter on the pavement In Brussels.

[ScouseSpaceCadet]

11 minutes ago, JeremyS said:

That’s exactly how my specs looked last when when I stepped on them having tripped over an abandoned scooter on the pavement In Brussels.

Jeremy if you missed a scooter, the glasses probably weren't much good anyway... or was it dark and you stepped out of a club's 80s night wearing sunglasses? 😎

[pystab]

Good point about dark adaptation, but I still have to look at the chart at some point. Besides, my back garden is overlooked by street lights so I never have any night vision to lose! Should I find myself somewhere actually dark, I'd dim and redden the phone screen, and switch it off anyway once the object to view's found.

I like the flip-up frames idea, and cheap off-the-shelf glasses would make damaging them less of an issue. I'd still prefer to do without glasses altogether though.

[Ouroboros]

I use a lanyard too like Bosun21 above. Works for me and at least I know they’re safe. 

[Malpi12]

On 03/07/2022 at 11:54, pystab said:

 the glasses-on-glasses-off hokey-cokey is very irritating,

I'd like to know what other solutions may exist for this problem!

Yes, very irritating.

Buy cheap reading glasses from the £1shop (actually £1.50 !)
Remove one lens from the glasses for your scope looking eye.
Use the remaining lens side for your reading eye.
Works a treat for me.

For the future, to do job : add a flip-down dark patch to preserve the dark side (to save having to remember which eye to close 🤣 !   )

 

Edited July 5, 2022 by Malpi12

[Ouroboros]

That’s quite a good idea. Could lead to speculation from the neighbour, when conversing over the garden fence, as to why you keep winking at them. 😉

[BoredPhil]

As someone who has finally succumbed to needing reading glasses, this is a v helpful discussion! If clouds clear tonight I now know what to expect - one of the main reasons I put off the opticians was the thought of working out how to observe.

I'm also an advocate of multiple cheap pairs - I bought 4 pairs online and I'm down to 2 after a week... I'll get some decent ones once I've got better at not losing/dropping them. Hopefully I still have a pair after tonight...

[munirocks]

I , too, hate the whole glasses on-off-fogging-pocketing-dropping thing at the scope. I'm near-sighted and wear vari-focal contacts, although I'm sure that a large proportion of the "vari" in "vari-focal" comes from mono-vision, where my left eye is optimised for infinity and my right eye is optimised inward half a diopter for reading. However my right corrected eye is not optimised enough for reading setting circles in the dark so for a stargazing session I remove my right contact and use my right near-sighted eye for reading and looking through the scope, with no contact lens to degrade the view. I use my left eye (infinity, with the contact still in) for naked eye and finder scope. 

If you have the opposite far-sighted problem then you could go for a different  monovision option. Use one eye as is for infinity, naked eye, finder scope, and main scope. And use one contact lens in the other eye optimised for up-close reading in the dark. 

I have found that for many activities, monovision obviates the need for glasses so effectively that it's almost like being young again. You have two eyes, and monovision is like a Swiss army knife that leverages that fact.

[Carbon Brush]

Very good comments from the above. Something else to throw in.

Varifocal lenses are full of compromises. Your brain 'fills in' for a lot of their restrictions.
They are worse if the prescription includes an element of astig correction.
However, a standard (no astig) varifocal is still going to introduce errors along the vertical axis.

Suppose you have zero distance correction and + 4 dioptres near correction. An extreme I know, but this to provide an example.
The lens may be 30mm top to bottom. Ignoring the extremes (5mm top & bottom), this means the lens goes from no correction to full correction over 20mm.
In other words 1 dioptre per 5mm of vertical movement.
You will get a clear view only if the eyepiece exit pupil is small compared to the (0.2 dioptre per mm) distortion on the specs.
A 5mm exit puil (or light cone) from the eyepiece will have to pass through specs with 1 dioptre difference top to bottom.

I realise that I have given an extreme with 4D near correction, a linear progression and a not very tall lens.
But for many observers, the effects are there, albeit a bit smaller.

You are better choosing specs with huge 'patio door' lenses popular in the 80s. That gets the rate of change down.
Also look at the correction maps for the lenses.
A decent optician will be able to show you what look like contour maps for where the lens corrects.
Some are gradual, some are almost bifocal with a rapid transition zone that you can aviod using at the scope.
Some have a narrow reading region so you can thread a needle, but not read a page.
If you don't ask.........

Another effect to consider is the chromatic abberation. This is more of an issue if you choose lenses with a high refractive index.
These are popular to get thickness, and therefore weight, down.

I use fixed contact lenses to remove astig then use reading specs as necessary to see the small stuff - like a screen.
££ shop readers in a pocket don't fog and I can afford to leave them around the place.

If I didn't get on with contact lenses, I would consider dioptrix or use fixed focus specs to remove astig.

HTH, David.

[jjohnson3803]

Although I usually keep my glasses on to observe, I'll sometimes use a lanyard if I'm switching on / off.  

I recently upgraded my SkySafari to Version 7 (?) and the coords display on my phone screen are too small to read easily in red mode even with my progressives.  I was about to start using a hand magnifier, but I discovered early this morning that my iPhone has a magnifying function that kicks in with a 3-finger triple tap.  Quite handy even if it makes me feel apprehensive that I'll be browsing the large print section at my local bookstore soon.

Edited July 12, 2022 by jjohnson3803

[scarp15]

It is a tricky one, bordering on comical, faffing with reading glasses etc in this situation. I keep my glasses in the car, so that they don't ice or mist over. When I'm out on a dark sky trip, I depend mostly on a good hand held magnifier for reading charts. Retaining dark adaption is essential on these trips, therefore very dim red light setting and paper charts, the magnifier does a good job at picking out detail. 

 

 

 

[Gonariu]

I am both nearsighted and long-sighted and with a slight astigmatism. To observe through the telescope I always take off myopic glasses, to consult maps and make a pencil drawing of what I observe I have a focus point about 10 cm (more or less 4 inches) from the eyes. The astigmatism I have does not cause me problems, I have read that if someone who is very astigmatic can take off his glasses if he observes at high magnifications.

[Leafus]

Monocle?

It is very annoying. I trash reading glasses so get eyecedar 6 for £20 off Amazon. Great optics for price. I get through maybe 24 a year. 
 

At some angles at higher altitudes I just slide them to the end of my nose. No problem. But lower I put them on CPC base.

 

 

Edited July 13, 2022 by Leafus