Pupil Dilation Drops

[gaseous]

Are there any optometrists/ophthalmologists in the visual forum? I’m keen to know if taking pupil dilation drops prior to an observing session would make my pupils dilate any more than might naturally be expected after full dark-adaption, to see if it makes a difference detecting faint fuzzies. Maybe just one eye, to test the difference.
Having said that, the list of potential side effects is pretty extensive, and not the kinds of things you’d enjoy experiencing at night at a dark site miles from help. One particular brand’s potential side effects include experiencing “false beliefs that cannot be changed by facts”, which is a pretty remarkable effect from putting a drop of liquid in your eyes. I imagine you’d win few friends if you started loudly expounding the intellectual virtues of flat-earthers in the middle of a star party. I’m reminded of a scene from Monty Python and the Holy Grail: “and that, my liege, is how we know the earth to be banana-shaped”…

[leon]

Hey Pat, I am not a optometrists/ophthalmologists or any eye specialist, but that sounds like a bad idea, just go out a half hour or so before you start doing stuff, look up for a while and let your eyes adjust normally.

Just my two cents worth.

Leon

[gaseous]

Cheers Leon,


Yes I'm normally pretty fastidious about my dark-adaption, I was just having some random pupil-related flights of fancy. It sounded plausible in my mind until I saw the staggering list of undesirable side effects, so I think I'll leave the theory untested.

[Startrek]

My experiences with Pupil Dilation……,
I have Myopia , Astigmatism in one eye , PVD (Peripheral Vitrious Detachment ) and borderline Glaucoma so it’s an annual trip to the Ophthalmologist for comprehensive eye testing including eye drops to dilate your pupils.
My general eye sight is ok wearing glasses and I can observe through eye pieces without wearing glasses ( Televue eye pieces ) using my non astigmatism eye and still pick up faint detail like the Trapezium in M42 on a moonless night.
However when I have the drops to dilate my pupils ready for the gamut of eye tests , my eye sight even wearing glasses is terrible both in a darkish room and of course in artificial light ( it’s really painful to view in daylight or artificial light with your pupils dilated.
From my experiences over the years, medically dilating your pupils to hopefully improve your Astro vision would be a complete waste of time IMO
Best leave Mother Nature to naturally dilate your pupils accordingly.
I’m sure a professional Opthalmologists would not dilate your pupils for the purposes of visual astronomy. In any case I have to wait 30 to 40 mins after my examination to be allowed to drive home.

Cheers
Martin

[gaseous]

Thanks Martin, yes blurred vision being one of the side effects sort of defeats the whole purpose of it. Sounds like you've got quite a list of eye issues to be going on with!

[mental4astro]

One member of my Club is an ophthalmologist. This was one question we put to him. There is no advantage to be gained from these drops. Why? You are forgetting that it isn't just the pupil that the eyes have, but a sensitive retina that is what is actually needing the time to adjust for the dark. The pupils will fully dilate very quickly. It is the retina that takes longer to adjust. And this process cannot be accelerated. So now you see why the is nothing to gain from such drops.

These drops also won't open your pupils any more than they can. While our pupils typically get smaller as we age, the drops won't have the pupils open up to the size when you were 15 years old. So again, nothing to gain.

[gaseous]

[QUOTE

These drops also won't open your pupils any more than they can. While our pupils typically get smaller as we age, the drops won't have the pupils open up to the size when you were 15 years old. QUOTE]




This was the crux of my line of inquiry. Thanks Alex.

[EpickCrom]

Hi Patrick, an interesting enquiry and one that I've pondered
on as well. Love the line about expounding the virtues of flat earthers at star parties :rofl:

[OzEclipse]

Hi Patrick,

My mother had a retinal detachment in middle age and so I get an annual detailed retinal exam using those drops. They are horrible, they sting, and leave the vision blurred and with vision blurred like that, you are not permitted to drive for 2-3 hours afterwards. I've always assumed that the vision is blurred because they are a muscle relaxant and so they not only relax the pupil contraction muscles but also the focussing muscles of the lens. I've never tried but I really doubt you will get a clear view of anything through a scope.

You are much better off accurately measuring your pupil dilation and then matching the exit pupil (ExP) of the telescope to the dilation of your pupil to ensure 100% light transmission to the eye. This is especially important as you age and your pupil dilation starts to reduce.

A couple of examples: -

At age 60, your maximum dilation is typically around 5mm.

With a 5mm pupil dilation, the brightness of deep sky objects viewed through a pair of 10x42(4.2mm ExP) and 9x63(7mm ExP) binoculars is almost identical. The 9x63 binoculars are transmitting equivalent to a pair of 9x45mm binoculars. But if you step up to a pair of 15x70(4.6mm ExP), the image is vastly brighter because the light from the full 70mm is reaching your retina.

If you have a 16 inch f4 telescope and you use a 40mm eyepiece(10mm ExP), only 25% of the light from the telescope is entering your eye and your eye is only receiving as much light as you would get from that same 40mm eyepiece through an 8" f8, or a 20mm eyepiece through an 8" f4, or a 25mm eyepiece through an 8"f5.

I have recently written a detailed article here that talks about pupil dilation, exit pupil and observing strategies for maximising light transmission from the telescope for aging astronomers. Aging in this context is 30 years of age onwards.

You can download a PDF copy here: -
https://theskysearchers.com/viewtopic.php?p=281281#p280632

There is an extra chart that I have put together since writing the article that aids with choosing efficient eyepiece combinations with various telescopes at different ages.
https://theskysearchers.com/viewtopic.php?p=281281#p281071


cheers

Joe

[floyd_2]

What an excellent article Joe. Thanks for sharing it with us all mate. The final practical example in Appendix 3 is sort of scary for the oldies with big scopes. A lot of us dream of having a retirement scope of 18"+ for visual, but it sort of doesn't make sense to move in that direction in later life as alluring as it is.

Like others here, I've already moved on to EAA and traded eyepiece time for screen time. Certainly I've seen more with EAA than I ever did visually, but it has been at the expense of the enjoyment of relaxing under the stars in my observing chair enjoying the views through my (now sold) Naglers.

I guess we all have to make allowances for being fortunate enough to get old and EAA for me has been a minor one that's opened my eyes to so much more viewing in recent years. This is especially so given the endless march of light pollution into my area.

[OzEclipse]

Thanks Floyd. The aim of the article is not to make you give up visual observing but to make you aware of how you can lose light and use strategies to make sure you don't. I have an 18" f5.5 and I live in a location that has no light pollution but varies from Bortle 1-3 depending on sky transparency. Visual observing is still a highly rewarding activity. An example is the Dumbbell Nebula. I don't just see the dumbbell lobes but also the fainter nebulosity in the full shell. So it looks roughly circular with the Dumbbells superimposed on the roughly circular shell.

I don't use 40mm eyepieces in the scope any longer unless I am hosting a much younger observer. A few years ago, I bought a second hand Tak LE50 eyepiece for a friend of mine. He had been looking for one for a long time but was in surgery having a pacemaker fitted. Just for giggles I tried it out using an 8" f9 Cass for comparison.

The brightness of a view of Eta Carina through the 18" with the LE50 closely matched the view through my 8" f9 Cassegrain because of light loss due to the nearly 9mm exit pupil. I am just on the verge of aging out of my 31mm Nagler in this scope. It currently gives me the light of a 15.5" scope so still an impressive wide field. In future, I might consider moving to a 21mm Ethos
for my wide field goto eyepiece which will give me a similarly wide field to the 31mm and transmit 100% well into my 70's and perhaps 80's by which time, the scope will be far too big and heavy for me to set up.

As you get older, consider moving to ultra-wide shorter focal length eyepieces. Sell off the long focal length models.

Cheers

Joe

[gaseous]

Thanks Joe, some great information there.

[jc3]

Yes, best not to opt for chemical help.