Astronomy with astigmatism

[Northants Simon]

I have astigmatism which means without glasses the stars look star shaped, Iv'e struggled with using binoculars as they aren't easy to use with glasses on, and without them I can't see the stars as pin points of light. I'm now wanting to buy a telescope but am worried I might struggle with this problem. Since astigmatism is common I'm sure many of you will have overcome this problem. Is there a particular range of EP's that work better when wearing glasses? 

[kalasinman]

Certainly no expert here, but just reading about this subject. In the past , easier to answer as to type, but with adbances in optics, that's changing. The important aid for glasses wearers, like myself, is the amount of eye relief. This can usually be found with the specifications of the EP. I see that a minimum of 15mm is usually recommended.

[ronin]

I have astigmatism and to be honest I never think about it, I suppose it depends on the amount and maybe I have a small amount.

Simple answer is you get eye pieces that have reasonable eye relief and wear your glasses.

I sort of do both, with and without glasses.

Puzzled that you cannot use binoculars as I have 2 sets and they are the one thing I always have my glasses on for as they cannot quite correct for the short sight.

Eyepiece that are "suitable" and not overly costly are the BST Starguiders and the Celestron X-Cels.

They are designed with eye relief of 15-16m and 17-18mm each, plossls do not have fixed eye relief, theirs is about 2/3 of the focal length, so less then say 15mm FL and you could have problems, could have problems at 15mm FL with a plossl.

There are some that allow the addition of a corrector for astigmatism but they are more costly and you then need the corrector.

As it generally means putting the spectical lens in contact with the eye cup I suspect that glass lens not plastic would have a better life.

Will ask are you sure that you absolutely need to keep your glasses on?

I just find that things do come out sharp without my glasses.

What scope are you thinking of or have?

If you say you have a reflector and there are pointy bits on the stars that could be the diffraction spikes.

[Oddsocks]

I have been using Dioptrx astigmatism correctors for Televue eyepieces for many years.

T.V. eyepieces are expensive and the astigmatism correctors aren't exactly cheap either but it is an elegant solution to the problem and has the bonus of preventing accidental scratch damage to your glasses since you no longer need them for observing.

The Dioptrx correctors are interchangeable between eyepieces so you don't need to buy one for each eyepiece.

If you did go for them you need to ask your optician to measure your astigmatism in low light conditions since astigmatism is generally worse as your pupil expands.

Here is a link to the Dioptrx info page of a UK supplier of T.V. eyepieces.

http://www.green-witch.com/televue-dioptrx-2428-p.asp

[LittleSkink]

We have astigmatism in our family but myself and my 9yo daughter manage just fine, mostly

Our (her) scope is a Skywatcher Heritage 100P. The standard 25mm "low power" eyepiece works ok for us but the 10mm "medium power" was very hard to use with glasses - we replaced that with a budget Skywatcher 9mm Long Eye Relief from ebay and it is much better. For not much over £100 we are happy with what we can see/do

How much were you thinking of spending and what do you want to look at? You can definitely get good mainstream "long eye relief" eyepieces in the £50 to £60 range, if you want to look at clusters etc (as we do) then wide angle eyepieces with good clarity towards the edge of the lens become more useful - we are still exploring how best to approach this so will watch this thread with interest

[michael.h.f.wilkinson]

I simply keep my glasses on and have invested in long-eye-relief EPs. Eye relief is the distance between eye lens of the EP and the exit pupil (which is where your eye should be placed for optimal views. In my personal experience EPs with 20mm eye relief (ER) are optimal, 15-16mm eye relief is borderline usable, and anything shorter is not. The precise figures will vary between observers.

These EPs do tend to cost a bit more, but the TS HR Planetary EPs are quite affordable. Long focal length (24-32mm) Plossl and orthos are fine. The Vixen LV(W), NLV and SLV are fine, as are Delos, and the Type 4 Naglers.

[cotterless45]

Never saw the effects, but now I have thinned down glasses, I try and keep them on when observing. It is possible to move away from the ep, probably further than you thought possible. Certainly worth a try,

Nick.

[laudropb]

When using binoculars you have to turn the rubber eye cups down, or if they have solid eye cups push them down to their lowest setting. I have astigmatism but have used binoculars for many years without any problems

[kerrylewis]

Hello Simon - you are probably not far away from me!

There have been a few threads on here about astigmatism and observing. I started one recently re the possibility of using contact lenses and, in fact, I have just returned from an appointment with the optician.

I have astigmatism in both eyes but one (the right) is worse than the other. I also need glasses for reading so I have varifocal lenses. But for some reason and despite everything that I have read about long eye relief etc, I simply cannot get used to using glasses to observe either with binoculars or a telescope. I always feel that I cannot get in close enough somehow. But I then need glasses to read the handset, use the Tetrad and read a star chart or make notes. So I am constantly putting my glasses on and off. 

So I decided to try contact lenses. I have tried some in this morning and was simply amazed how comfortable they were despite never having worn them before. The ones I tried were not the final prescription that I agreed with the specialist optician today and I will try those next week. They consist of one for one eye for distance/astigmatism correction and one for the other for reading/astigmatism. This sounds odd but I tried it this morning with the optician's specs and it seems to work.

I can't help feeling that I am not getting the best view out of my scope by not wearing glasses so I will be interested to try them.

I have one of the TV Dioptrix correctors that I bought some time ago but it only fits my 6mm Radian and, to be honest, I can't see much difference. I have since learned that astigmatism has less effect on short focal length eyepieces (and the 6mm is the shortest I have!) but I didn't know that at the time. I am reluctant to buy more expensive TV eyepieces just to fit the Dioptrix! 

I am not worried if the contact lenses don't really improve observing much  - at least they will mean that I don't have to keep putting glasses on and off. Also, in the brief trial this morning, it felt very liberating just walking around after years of wearing glasses.

I will report further on the lenses. I am not suggesting that you need those - it could be that long eye relief eyepieces and glasses will work well for you.

Cheers

Kerry 

[Astrosurf]

I have astigmatism and just generally ageing and tired eyes. It's one of those situations where I do what's needed for every situation, especially when I'm tired. I leave my glasses on or off as needed. I use Hyperions which are lovely and are on offer at the mo:

http://www.firstlightoptics.com/baader-planetarium/baader-hyperion-68-degree-eyepiece.html

Alexxx

[Astrosurf]

+1 for the contact lenses, if you can tolerate them. I wish I could!

[Northants Simon]

Wow, I hadn't expected so many replies so quickly, thank you. 

The telescope I'm looking at is the Skywatcher Heritage 130P, which seems to offer the best value for money, I have about £70 left in my budget for an EP, books etc. 

[Charic]

It would be a Free first night with many astronomy clubs. Your already suspicious of the results due to your experience using binoculars. Locate your local astronomy club, find out where and when they meet, make sure the weather is good, and go and try a telescope before you spend anything. In one night alone, you should tell if a telescope is suitable for you, if the image is correct, and importantly, maybe the type of telescope you require.

You dont have to join a club, but use the chance to speak to folk, and try some kit. Good luck.

[kerrylewis]

Simon

I see that you also have another thread running on choosing a telescope. If I am near you (Northants is quite a big county!) and I can help in any way - please let me know. Best to PM me re locations

Cheers 

Kerry 

[michaelmorris]

^{I know this is a little off-topic, but you mentioned that you weren't able to get on with binoculars with glasses.  I have a pair of Optircon 8 x42s (Countryman HDs I think) and for the first time in my life and I can use binoculars whilst wearing glasses}

[Dave]

Hi Simon,

I tried contact lenses, vari-focals and nothing worked for me with my astigmatism.
Everything was far too awkward and I didn't get in with contacts.
Four years ago I finally had enough and opted for laser surgery.
For me it worked a treat. My observing is almost as good as I remember it in my teens.
I still need reading glasses, but that's age related.

Like Kerry, I'm probably not too far away either, so let me know if you want me to help in any way.

[greglloyd]

I have astigmatism as well. I've found that the Delos range of eyepieces work quite well for me (as they give well corrected views in the first place).

I've also read on the TeleVue website that most people can work out the exit pupil limit they can go too before astigmatism shows up in the eyepiece (smaller exit pupils have smaller light cones and therefore hit a smaller, more central part of the eye meaning your astigmatism may not show up).

I have the 14mm and 17.3mm Delos eyepieces and find that my astigmatism is so small with these that I can get away without wearing my glasses with them. The very sharpens ever so slightly with glasses on, but it's very very good even without them. The 14mm is the sharpest with an exit pupil of around 2.8mm. The Delos has 20mm eye relief making them comfortable with glasses on.

I have an ES MaxVision 28mm with an exit pupil of 5.65mm and the view in that without glasses on is comical. Stars have huge diffraction spikes in all directions and wildly changing shapes as I move my head around!! Stick the glasses on and everything is fine (except for some coma) :-)

[greglloyd]

Hello Simon - you are probably not far away from me!

There have been a few threads on here about astigmatism and observing. I started one recently re the possibility of using contact lenses and, in fact, I have just returned from an appointment with the optician.

I have astigmatism in both eyes but one (the right) is worse than the other. I also need glasses for reading so I have varifocal lenses. But for some reason and despite everything that I have read about long eye relief etc, I simply cannot get used to using glasses to observe either with binoculars or a telescope. I always feel that I cannot get in close enough somehow. But I then need glasses to read the handset, use the Tetrad and read a star chart or make notes. So I am constantly putting my glasses on and off. 

So I decided to try contact lenses. I have tried some in this morning and was simply amazed how comfortable they were despite never having worn them before. The ones I tried were not the final prescription that I agreed with the specialist optician today and I will try those next week. They consist of one for one eye for distance/astigmatism correction and one for the other for reading/astigmatism. This sounds odd but I tried it this morning with the optician's specs and it seems to work.

I can't help feeling that I am not getting the best view out of my scope by not wearing glasses so I will be interested to try them.

I have one of the TV Dioptrix correctors that I bought some time ago but it only fits my 6mm Radian and, to be honest, I can't see much difference. I have since learned that astigmatism has less effect on short focal length eyepieces (and the 6mm is the shortest I have!) but I didn't know that at the time. I am reluctant to buy more expensive TV eyepieces just to fit the Dioptrix! 

I am not worried if the contact lenses don't really improve observing much  - at least they will mean that I don't have to keep putting glasses on and off. Also, in the brief trial this morning, it felt very liberating just walking around after years of wearing glasses.

I will report further on the lenses. I am not suggesting that you need those - it could be that long eye relief eyepieces and glasses will work well for you.

Cheers

Kerry 

Hi Kerry,

Contact lenses can be a good solution. I previous used lenses for a while and the lack of having to wear glasses is great. In the end, it didn't work for me on astro as I have slightly dry eyes and it seems that when you work your eyes harder (as in for astro) then the lenses become uncomfortable and you start to find visual disturbances in the view due to the lenses becoming dry on your eyes, etc. Hopefully you won't have that problem. If it wasn't for them becoming uncomfortable for me, then I would definitely still be using them today.

[michael.h.f.wilkinson]

One warning on contact lenses for certain kind of astigmatism. I ave cylindrical astigmatism, so stars look like rods. For a soft (toric) contact lens to correct this in needs to be in a very specific orientation. Some are balasted to make one side heavier, to ensure the right orientation. This can mean that you cannot lie on your side and watch TV, as the lenses will start to rotate with respect to your eyes. Some scopes (EQ-mounted Newtonians) invite or require the user to tilt their heads in a similar fashion. This may cause trouble. Note that not all contact lenses for astigmatism share this problem. It is just something to be aware of.

[baggywrinkle]

I have astigmatism and I often worjkm without glasses and do not seem to notice the problem too much...

[Jonimac25]

I suffer from astigmatism, if I'm out with the scope I put in a pair of toric contact lenses, they are daily ones so just chuck them away before I go to bed! Lenses are a bit fiddly at first but you soon get used to them!

[Northants Simon]

Hi Simon,

I tried contact lenses, vari-focals and nothing worked for me with my astigmatism.

Everything was far too awkward and I didn't get in with contacts.

Four years ago I finally had enough and opted for laser surgery.

For me it worked a treat. My observing is almost as good as I remember it in my teens.

I still need reading glasses, but that's age related.

Like Kerry, I'm probably not too far away either, so let me know if you want me to help in any way.

I think you are almost my neighbour, I'm in Higham Ferrers on the Kings meadow estate and I'm thinking it's probably you with the observatory in the garden? I was going to pop up to the club meet at Chelveston, but saw it was cancelled due to cloud. 

[Dave]

I think you are almost my neighbour, I'm in Higham Ferrers on the Kings meadow estate and I'm thinking it's probably you with the observatory in the garden? I was going to pop up to the club meet at Chelveston, but saw it was cancelled due to cloud.

You might be right. I'm not involved very much with the local club as I have too many other commitments. I also attend Bedford and Northampton Astro socs if you want to come along to one of them with me sometime. Or maybe pop by sometime. Send me a personal message with your contact details and I'll give you a shout.