Astigmatism and exit pupil (2 Viewers)

[looksharp65]

Another ?" Before writing my reply above, I tried my scope with three different eyepieces, with 3 mm exit pupil, with 2 mm exit pupil, and finally with 1.3 mm exit pupil."
Lars was this looking at stars?

Thanks for any reply!!

Well, I think it was cloudy, and dark too, so I had to focus a streetlamp with lots of details like dirt specks on its cover glass, and some spiderweb too.

Anyway, it came as no surprise to me that the sharpness was better when using my spectacles.
Secondly, I could see that a smaller exit pupil did not help at all in masking the astigmatism.

//L

 

[mooreorless]

Thanks for your reply!!! I will say my presbyopia is moving out further on both eyes and the supposed distance used to check eyes is not always far enough for distance viewing as a person ages.

 

[looksharp65]

Thanks for your reply!!! I will say my presbyopia is moving out further on both eyes and the supposed distance used to check eyes is not always far enough for distance viewing as a person ages.

Two different things in one sentence. I'll try to reply.

1)Yes, presbyopia has a natural progression, but once all your accommodation is gone, any need of even stronger reading glasses emanates from an increasing hyperopia/decreasing myopia.
Edit: At the age of 60, very little accommodation facility remains, though some individuals actually show remarkably more.

2) Fine-tuning is an art, and mistakes occur more than once. I often take my patients to a place where they can see a hundred meters or so, and I show them two or three alternative powers just to make sure. Then again, after having made the decision on distance powers, occasionally other problems occur, like reduced sharpness at closer distance.

//L

 

[mooreorless]

Thanks for your reply. After reading some of your replies on here about "things" on the eyes, I don't think Lasik surgery will ever affect your business one bit. Sounds like you go the extra mile to help out patients. :t:I think I am not the typical patient either.

 

[Winterdune]

I'm sorry to piggy-back on this thread but I wondered if you could answer a related question, Looksharp?

I'm now 49 and was a contact lens wearer for many years, but gave up about seven years ago because of my increased astigmatism and limited success with torics to correct it (they were never really stable enough) and because my eyes seemed to have become dryer and less tolerant of lenses. Gas permeables were a total non-starter for me.

I was just wondering if there have been any advances in toric lenses now and if so whether I should try them agin - it sure is a total pain having to birdwatich with specs in the rain!

Are there any makes/designs that you would suggest trying?

Many thanks, and sorry for the hijack!

Sean

 

[Winterdune]

Oops! I seem to have found the answer to my question in the previous post in this thread:
http://www.birdforum.net/showthread.php?t=189822&highlight=astigmatism

Many thanks,
Sean

 

[looksharp65]

Oops! I seem to have found the answer to my question in the previous post in this thread:
http://www.birdforum.net/showthread.php?t=189822&highlight=astigmatism

Many thanks,
Sean

That's where I answered. :t:

 

[John Russell]

Send John the bill.

Sorry again that my stupid question started an avalanche.
I guess optics geeks are to optometrists what hypochondriacs are to physicians.

John

 

[looksharp65]

Sorry again that my stupid question started an avalanche.
I guess optics geeks are to optometrists what hypochondriacs are to physicians.

John

John,

I haven't seen any stupid question from you or someone else here. If I can give some advise on use of contacts or spectacles, I'm happy.
You know, I am familiar with the human vision and I answer some of these questions every day, or more.

There is a certain difference between physical optics and ophtalmic optics, and the same rules cannot be applied. Binoculars are a special and very interesting case where these two worlds have to meet and co-exist.

Usually I'm not interested in giving advise in my leisure time, but you all can regard it a BirdForum member privilege.
In any case, your local optometrist will be the one to help you when it's time.
So you can't sue me for giving bad advise

 

[mooreorless]

"I guess optics geeks are to optometrists what hypochondriacs are to physicians."

John that sure is true. I will have to try to remember that.

Sorry Lars for all the questions and thanks for your help!!