TheSkySearchers

Posted: **Thu Sep 02, 2021 12:14 am**

I wonder if this might be a useful skill for visual astronomers to master?
"Man Can Change His Pupil Size on Demand, Something Scientists Thought Was Impossible"
https://www.sciencealert.com/this-germa ... on-command
(as linked from Instapundit.)

Posted: **Thu Sep 02, 2021 2:58 pm**

This is easy to accomplish with a light at night that causes the pupil to shrink.
You voluntarily turn the light on.
I'm just saying......

Seriously, though, the dilation of the pupil is part of the autonomic nervous system, so beyond your conscious control.

Posted: **Fri Sep 03, 2021 12:11 pm**

It would be nice to be dark adapted in a matter of seconds.....

Posted: **Fri Sep 03, 2021 1:46 pm**

KingNothing13 wrote: ↑Fri Sep 03, 2021 12:11 pm It would be nice to be dark adapted in a matter of seconds.....

Yes. I think most of that dark adaption occurs in the retina, not the pupil. But I wouldn't mind having some ability to consciously control my pupils. I mean, not that it could ever compare to being able to wiggle one's ears...

Posted: **Fri Sep 03, 2021 1:49 pm**

Well, now I'm wondering if any among us who might be ophthalmologists get naughty with those dilating drops?

Posted: **Fri Sep 03, 2021 2:09 pm**

KingNothing13 wrote: ↑Fri Sep 03, 2021 12:11 pm It would be nice to be dark adapted in a matter of seconds.....

You do get dark adapted, where pupil size is concerned, in seconds.
But since 99% of dark adaptation occurs on the retina, not the pupil, it still takes 30-45 minutes to fully dark adapt, and some improvement is noted after 2 hours.

Posted: **Fri Sep 03, 2021 2:14 pm**

notFritzArgelander wrote: ↑Fri Sep 03, 2021 1:49 pm Well, now I'm wondering if any among us who might be ophthalmologists get naughty with those dilating drops?

Those drops affect the small muscles that control the lens as well, so acuteness of vision goes down with their use.
But pupil size isn't really important in dark adaptation.
An 8mm pupil admits 4x the light of a 4mm pupil. Ooh, 4X.
But dark adaptation on the retina has been measured to be up to a 90,000x improvement in light sensitivity in a lab setting.
Even if it's only a third of that in the field, you can see that pupil diameter is NOT where dark adaptation occurs.

Posted: **Fri Sep 03, 2021 3:03 pm**

Don Pensack wrote: ↑Fri Sep 03, 2021 2:14 pm
notFritzArgelander wrote: ↑Fri Sep 03, 2021 1:49 pm Well, now I'm wondering if any among us who might be ophthalmologists get naughty with those dilating drops?
Those drops affect the small muscles that control the lens as well, so acuteness of vision goes down with their use.
But pupil size isn't really important in dark adaptation.
An 8mm pupil admits 4x the light of a 4mm pupil. Ooh, 4X.
But dark adaptation on the retina has been measured to be up to a 90,000x improvement in light sensitivity in a lab setting.
Even if it's only a third of that in the field, you can see that pupil diameter is NOT where dark adaptation occurs.

Yes, I know that dark adaptation happens at the retina. My question was whether anyone heard of folks who abused the drops. People do wacky things. I’ve heard of folks hyperventilating and overcaffeinating in an effort to squeeze a little more out of the retina, for instance.

Posted: **Fri Sep 03, 2021 4:21 pm**

I have read of people who used the dilating drops in the field and found their vision blurred.
They didn't get back their acuity for many hours after the drops were administered.
And, of course, since we all have terrible astigmatism in the eye when the pupils are dilated to large sizes, even non-glasses wearers would find their vision wonky, needing astigmatism correction and possibly spherical as well.

Posted: **Fri Sep 03, 2021 4:58 pm**

Don Pensack wrote: ↑Fri Sep 03, 2021 4:21 pm I have read of people who used the dilating drops in the field and found their vision blurred.
They didn't get back their acuity for many hours after the drops were administered.
And, of course, since we all have terrible astigmatism in the eye when the pupils are dilated to large sizes, even non-glasses wearers would find their vision wonky, needing astigmatism correction and possibly spherical as well.

Well, that doesn't sounds like fun at all.

Posted: **Fri Sep 03, 2021 5:50 pm**

AntennaGuy wrote: ↑Fri Sep 03, 2021 1:46 pm
KingNothing13 wrote: ↑Fri Sep 03, 2021 12:11 pm It would be nice to be dark adapted in a matter of seconds.....
<snip> I mean, not that it could ever compare to being able to wiggle one's ears...

Hey, I can do that rather well.

Posted: **Sat Sep 04, 2021 8:53 pm**

John Fitzgerald wrote: ↑Fri Sep 03, 2021 5:50 pm
AntennaGuy wrote: ↑Fri Sep 03, 2021 1:46 pm
KingNothing13 wrote: ↑Fri Sep 03, 2021 12:11 pm It would be nice to be dark adapted in a matter of seconds.....
<snip> I mean, not that it could ever compare to being able to wiggle one's ears...

Hey, I can do that rather well.

Hey! Me too. I also have a devastating one-raised-eyebrow that has been described as "the basilisk's glance" by literary friends.

Posted: **Sun Oct 17, 2021 6:52 pm**

I remember doing this when younger. Stand in front of a mirror and change the size of my pupil. I didn't achieve the degree this fellow can but it was noticable.

Posted: **Sun Oct 17, 2021 9:42 pm**

notFritzArgelander wrote: ↑Fri Sep 03, 2021 1:49 pm Well, now I'm wondering if any among us who might be ophthalmologists get naughty with those dilating drops?

I once asked my doc about getting them, he just laughed

Posted: **Thu Oct 21, 2021 11:09 am**

I've had those drops for the eye test and they are horrible. As mentioned, vision goes quite blurry. In fact they warn you before you go to came by taxi or have someone bring you because you won't be able to drive for a couple of hours afterwards. And agree with Don, the photochemical adaption is where most of the sensitivity occurs.

Of course, it's well-known that pupil's dilate with sexual arousal.....much more pleasant than those awful eyedrops......just sayin

Joe

Posted: **Thu Oct 21, 2021 1:03 pm**

OzEclipse wrote: ↑Thu Oct 21, 2021 11:09 am ...
Of course, it's well-known that pupil's dilate with sexual arousal.....much more pleasant than those awful eyedrops......just sayin
Joe

Ah, a passion for astronomy.

TheSkySearchers

Change your eye pupil size voluntarily?

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