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The performance of the Mk1 Eyeball

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Avocette

Avocette

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I've always been pleased to have pretty good eyesight. For 15 years I've needed to wear glasses for reading but so far the optometrist has always said that for distance viewing, glasses would probably be more of encumbrance than a help. My most recent prescription is +0.25 dioptre and +0.25 cylindrical correction for astigmatism for my right (dominant) eye and -0.25 dioptres with no cyindrical correction for my left eye.

I've been looking fairly hard during my observations recently, trying to be objective about what I see rather than just enjoying the view of interesting objects. And this starts with my eyes. In recent observations of Jupiter, I have been conscious that I see 'whiskers' extending from the bright planet, of similar nature but different for each eye. Am I correct in assuming that these are aberations due to my eyesight (with some dark adaptation of my pupils) and made visible in this rather critical test due to the very bright object and the dark background sky? And to what extent does everyone suffer such aberations?

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slickfonzy

slickfonzy

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I too have cylindrical astigmatism (-1.25) in both eyes and cannot observe without my glasses.  Any uncorrected defects in your vision (i.e. if you observe without glasses) will always be much worse with dilated, dark adapted pupils.

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LukeSkywatcher

LukeSkywatcher

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I wish the optician i had check my eyes about 2 months ago was so detailed (not that i'd understand it). She told me that with specs that my eyesight is better then the normal perfect vision of 20/20.

I asked....................."without glasses?".

She said "let's not worry about that".

Close-up, i can read a tattoo on a knat's backside. If i am catching a bus, the bus has to be about 3ft away from me before i can read what number bus it is.

It's fine now with my new glasses..................i can read car reg plates from about 30ft away.

I stil never wear glasses while observing. I keep meaning to try it but cant bring myself to doing it.

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Avocette

Avocette

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When you say whiskers are you saying they are in a cross pattern - if so it could be the spider holding the secondary?  On bright objects this is noticeable I believe in a reflector

No - just to be clear it's not diffraction spikes - I'm talking about the view from the unaided eye!

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Avocette

Avocette

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Just to clarify what I see with a bit more detail, I'm using the word 'whiskers' because the view of Jupiter I see with my right eye has these lines mainly between, say, using a clock metaphor, 7:30 and 10:30 on the left side of Jupiter, and 1:30 and 4:30 on the right side - so similar to the whiskers of a cat. My left eye also sees a similar effect but more randomly distributed around the circle of the clock although perhaps in contrast, more to the top and bottom. When looking with both eyes simultaneously, the images combine. The whiskers don't particularly shift in time (no 'twinkling') but probably do change a bit with blinking.

Any eye specialists out there?

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Ptarmigan

Ptarmigan

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Are you saying that cataracts would have such an effect?

No not me, I'm no optomthingyologist !

Just thinking aloud

and trying to find a reference to that effect that I thought I had read a long time ago but I, or they, may have been mistaken !!

Most pages say only about a cloudyness becoming apparent later. It is that word 'later' that was bothering me.

So I was waiting for someone to say "Nah, that's rubbish" or "Could be, get it checked out"

Or indeed for you to say "Only a month ago and nothing was said to that effect"

Hope I didnt cause you any undue fright.

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