varifocals

[AllanJ]

I wear varifocals which go from reading to distance most of the time, except for another pair of varifocals that go from reading to desktop computer screen distance (my "office glasses"), and a pair of reading glasses for, well, reading. When I am out with telescope I take my "main" glasses off to look through eyepiece, but wear a handy pair of cheap reading glasses on a neck cord.

[Paul M]

As I mentioned in post #2 I have had varifocals for some time (about 12/15 years) and don'e have a problem. Reading through this thread and seeing that many posters report distortion and odd feelings I can only think that I have been lucky or others have been supplied with inferior glasses. The thing that does present a problem is when doing some DIY tasks and looking up in restricted spaces as it is difficult to look through the bottom part of the lens.

I generally only buy top quality (Nikon) lenses and have always been aware of field distorions. I've got used to it over the years and for everyday use it's not noticeable really.

But for critical uses like focusing a telescope they are a pain!

I suppose it's down to the nuances of your particular prescription and the peculiarities of you vision.

[tteedd]

Wookie

0.25 is virtually nothing. A cyl this small may be measured at a different angle every time your eyes are tested. It is better in my opinion if they do not prescribe it. Mine is sometimes 0.25 and sometimes nothing depending on the Optometrist. Unscrupulous opticians can say that the angle has changed every time you go, Whoops £180 for new glasses.

Ted

[wookie1965]

Wookie

0.25 is virtually nothing. A cyl this small may be measured at a different angle every time your eyes are tested. It is better in my opinion if they do not prescribe it. Mine is sometimes 0.25 and sometimes nothing depending on the Optometrist. Unscrupulous opticians can say that the angle has changed every time you go, Whoops £180 for new glasses.

Ted

Thank you i have just paid £114 for these i am really struggling i think i will give them until next Friday then if still not used to them take them back and get two pair i want to give them a fair crack of the whip.

[hskygazer]

Thanks for the tips. I have worn varifocals on and off for over ten years. They are very good once you get used to them. However, I have found it is better to remove them when looking through binoculars but not when looking through a camera viewfinder or computer screen.

[bambuko]

It will take longer than couple of days to get used to them and for everyday use they are great (eventually ) so don't give up too quickly.

[Paul M]

My very first specs didn't work well for me.

I was a teen and knew my eyes weren't good enough to pass the driving sight test. So before starting driving lessons I got an eye test and my first ever specs. They were single vision for distance.

Wow! I'd forgotten what a tree full of leaves looked like and the stars came back!

Sadly while wearing them I couldn't read normal size print or even a car speedometer very well.

I went back to the opticians and said there must be a problem. They tested my eyes and checked the lenses and so everything was fine. I just needed to give them a chance.

I struggled on and only wore them for driving and stargazing. They never were right

For my next eye test I went to another opticians. He tested my eyes and I told him about the trouble I'd been having and while I still had the test rig on with my prescription dialed in he passed me the hand held thing with different size print on it and asked what was the smallest print I could read. I couldn't see any. Not even the largest.

"Ah! right then!" said he and did some more delving. 

Apparently I have very poor "accommodation", my own natural lenses don't make much effort to change focus. So my single vision lenses just changed me from short sighted to long sighted.

Currently my right eye is stuck at about 18" focus from my face but my left is becoming more longsighted at about 36". A bit too far for reading normal print. So although I can usually get by without specs for reading I will get a headache after too long.

Luckily I've always found varifocals very comfortable.

I always get the "ultrathin" light weight lenses and have anti reflection coatings on them.  Usually pay in the region of £250 - £300 but they throw in "free" prescription sunglasses

My advice to anyone struggling with a new prescription would be to get a second opinion. For the price of an eye test it's silly not to!

[wookie1965]

I have been going to the same optician for years its only the last 6 years i have needed two pair before that only need reading glasses, 2 years ago they said get varifocals and i said i would think about it and with swapping my glasses on and off and carrying them around i thought this time yes i would go for them. Whether it is me or the glasses i do not know i have only had them a day and a half i will give them some time i was going to say a couple of weeks but if the dizziness and headaches continue i will have to take them back when they open after Christmas, perhaps my brain has just got to get used to eye position.

[Eastridge]

I tried specsavers top notch varifocals last year and couldn't get focus in my left eye at all.  Went back they checked everything out , declared that my eyes weren't suitable for varifocals so I stayed with single vision.

Last week I went for annual eye test but in view of above went to local independent option for 'second opinion' and told them what specsavers had said.   The test there was much longer and included elements I have never had at ss, like looking at how my eye's coped with parallax effect and laser projected lines.   They have identified a problem but say that Zeiss Independent 2 lenses which are computer modelled to individual eyes and the specific frames from series of photos they took of me in the frames at the opticians should do the job.

Downside - £375 just for the lenses.

Should get them early Jan. and will see.

I have always been short sighted with high astigmatism, so sounds like whatever happens I will need to continue to use my existing single   vision  glasses for astro work.

Wookie - £114 sounds quite cheap for varifocals  so if you don't adapt it may be the quality of the lenses are not good enough for how your eyes like to work.  But considering with how much these ones are costing me I have a lot of sympathy with just going back to 2 pairs.

[kerrylewis]

Very interesting thread. I've had varifocals for some years and have never had any problems with them - except for astronomy. I have astigmatism which is much worse in one eye. - so I use the other at the eyepiece and ditch the glasses except for naked eye observing and the Telrad. My most useful accessory is therefore the cheap spec cord so they dangle round my neck and don't get trodden on - as happened once, very expensive!

[Astro Imp]

Very interesting thread. I've had varifocals for some years and have never had any problems with them - except for astronomy. I have astigmatism which is much worse in one eye. - so I use the other at the eyepiece and ditch the glasses except for naked eye observing and the Telrad. My most useful accessory is therefore the cheap spec cord so they dangle round my neck and don't get trodden on - as happened once, very expensive!

How do you manage the Telrad with varifocals on? I find I need to use it naked eye as I always get a double image especially near the zenith.

[kerrylewis]

Alan

The Telrad is tricky I have to admit. I find that without my glasses everything is unclear, and with the glasses I do tend to get a double image, as you say, but I have to ignore the 'wrong' one. I've always assumed that this must be 'normal' with the Telrad. Maybe I should try again without glasses?

Kerry

[BinocularSky]

Got varifocals a couple of decades ago when I found that the "line" of my new bifocals was slap bang on a good length, so the ball would "jump"; most disconcerting. The varifocals, it turned out, just created different problems, so I took to batting without my specs on.

 I must get a neck strap!   

Tried that. Just turns an expensive pair of spectacles into a pelican bib. I have taken to storing them in the sleeve-pocket of my observing jacket when they are not on my head.

My problem is hypermetropia and presbyopia with a dollop of astigmatism. I can cope without specs for general observing  but, if I want to do something critical like splitting a close double, I put my specs on and look through the top part of the lens. It's become second nature now.

[Astro Imp]

Alan

The Telrad is tricky I have to admit. I find that without my glasses everything is unclear, and with the glasses I do tend to get a double image, as you say, but I have to ignore the 'wrong' one. I've always assumed that this must be 'normal' with the Telrad. Maybe I should try again without glasses?

Kerry

Thanks Kerry, without the bifocals I only get a single image and its just about clear enough to be usable.

[wookie1965]

They did do all sorts of tests two red lines which side was the spot focused on left/right and then the same but horizontal, i do get help with prescription so i got £64  knocked off so in fact to buy the glasses would have cost £178 which i thought was quite expensive. As of today im still having problems with them and i have not even tried them with the scope, after all the great advice i will no doubt leave them off buy a neck strap so i know where they are t look at charts and maps if i keep them.

[bambuko]

... 0.25 is virtually nothing. A cyl this small may be measured at a different angle every time your eyes are tested...

looking through my last three ophtalmic prescriptions - they are all indeed different (done by three different opticians) with CYL varying between  +0.50/+0.25 and -0.50/-0.50 with AXIS measuring 30/20 or 100/45 or 105/90 (depending on the optician and the day... I guess?).

So if three opticians can't agree, how am I going to decide which it is?

[itmo]

AFAIK , near or farsightedness will be corrected by the scope focus mechanism, astigmatism wont . In most cases astigmatism is only a problem when the exit pupil is large enough to have significant difference in focus for different parts of the image. 

[Paul M]

looking through my last three ophtalmic prescriptions - they are all indeed different (done by three different opticians) with CYL varying between  +0.50/+0.25 and -0.50/-0.50 with AXIS measuring 30/20 or 100/45 or 105/90 (depending on the optician and the day... I guess?).

So if three opticians can't agree, how am I going to decide which it is?

From my own experience that there are variations in service between optometrists but I think an awful lot of the minor variation between prescriptions is down to the patient.

The subtle differences between "lens 1" and "lens 2" can be very difficult to perceive.

Sometimes I can't tell the difference between two particular settings. One time I might prefer one setting and next time I might prefer the other!

The optometrist can only work with your own perceptions and for most spectacle wearers the fine detail isn't that critical. 

[wookie1965]

Glad to report that i have now become accustomed to the new glasses as the more experienced on here advised me thank you very much, the headaches and dizziness  have gone  i can  now drive my car and reverse with no trouble. Thank you to all who gave there advice as usual the forum came up trumps.

[Astro Imp]

Great to hear everything worked out well.

[Fypunky]

I have been sitting on the fence with this thread, the two types of patients I dread are engineers and those with a prescription between -4 to -6 by far these are the most critical when it comes to vision, just wondering if astronomers are creeping into this category to lol.

My daughter and I have managed to get a few nights in and I have experimented a little myself, on her scope we have the red dot finder and the best solution I have found is contact lens in my left eye (i am short sighted ) so that eye sees the stars and my right eye is left uncorrected so it sees the rdf. 

My varifocals did create a few issues trying to locate the object etc. 

Good to hear your getting on with them, in most cases it is adaptation and patience. 

[bambuko]

... patients I dread are engineers...

as an engineer (retired) I know what you are talking about

[dph1nm]

Looking through my last three ophtalmic prescriptions - they are all indeed different (done by three different opticians) with CYL varying between  +0.50/+0.25 and -0.50/-0.50 with AXIS measuring 30/20 or 100/45 or 105/90 (depending on the optician and the day... I guess?).

So if three opticians can't agree, how am I going to decide which it is?

I once found a change in sign between two opticians so I queried it. Seems that there is some interchange between how your record axis and cyl  - as a result the two prescriptions were the same, even though the signs were different!

I use varifocals - I have no real trouble through an eyepiece, although I have always preferred to view without glasses.

I have found that the off-axis distortions (for the same prescription) can be very different with different makes of varifocals - and it is not always the expensive makes which are best.

NigelM

[CSM]

Very useful information Ted as I am about to have an eye test and want to change my glasses anyway - very scratched.  I started on varifocals at least 20 years ago and the local specsaver guy used me as a guinea pig with the new Nikon allround varifocals as opposed to the ones that merely corrected up and down which I couldn't get on with.  When I was happy he got himself a pair.  I have 3 pairs of glasses, the varifocal, a single 'long' distance one for Badminton and a single 'short' distance one for the piano.  With respect to the varifocal and long distance ones I am so used to them both that I have often have to look at the frame to remind myself which one I am using. 

Am hoping that the information given will enable me to get a better 'fit' of varifocals.