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#51 Jon Isaacs

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Posted 27 May 2020 - 05:03 AM

Did a bit of googling, and I can find no evidence that people with blue or green eyes have better low light sensitivity.

 

I think there is some evidence that people with blue eyes have larger dark adapted pupils on average. However, this does not translate into better low light sensitivity since the observations were not done at maximum exit pupil but rather a much reduced exit pupil.

 

Jon 



#52 RLK1

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Posted 27 May 2020 - 11:11 AM

Did a bit of googling, and I can find no evidence that people with blue or green eyes have better low light sensitivity.

 

All I can find is web sites where some people assert this as a claim, but provide no evidence. I also can't find anything on google scholar, but might be using the wrong search terms (and as soon as you mention 'night vision', you get a pile of research on electronics).

 

If you have something you can pass along I'd be interested to take a gander.

"How Eye Color Affects Vision. ... Lighter eyes, such as blue or green eyes, have less pigment in the iris, which leaves the iris more translucent and lets more light into the eye. This means that light-eyed people tend to have slightly better night vision than dark-eyed people.Sep 13, 2018" Brass Eye Center -

https://prezi.com/1t...-night-visions/


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#53 areyoukiddingme

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Posted 27 May 2020 - 01:30 PM

Hmm, looks like a school project with three participants representing the three eye colors. So not the strongest evidence.

 

I guess I'll have to keep looking.



#54 j.gardavsky

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Posted 27 May 2020 - 03:32 PM

My eyes are are blue, and I can see very good in dark, which is also helpful in this hobby astronomy.

 

However, this is still not a proof of a correlation,

JG



#55 russell23

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Posted 27 May 2020 - 04:07 PM

When I had my wisdom teeth out in 1989, for pre-surgery I was put in a room with another young man that was having his out.  At the time I weighed about 160 and the other kid weighed about 100lbs more than me.  
 

The doctor came in and told me it would take a lot to put me out because I was a redhead.  I thought he was joking but after the surgery he told me it took twice the anesthesia to put me out as that other kid that weighed 100lbs more than me.

 

There is research that backs that up.  So I’m not saying there is anything to this night vision thing, but there are unexpected correlations between genetic traits and things one would not expect.


Edited by russell23, 27 May 2020 - 04:08 PM.


#56 RLK1

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Posted 27 May 2020 - 04:37 PM

Hmm, looks like a school project with three participants representing the three eye colors. So not the strongest evidence.

 

I guess I'll have to keep looking.

In addition to what I've already posted, here's more:

https://www.almanac....ing-in-the-dark

  "Night vision is often better among people with blue eyes." https://www.nvisionc...ye-color-guide/

"What is known from an “evidence based” perspective is that individuals with light eyes (blue) tend to be more light sensitive." https://coavision.wo...ct-your-vision/


Edited by RLK1, 27 May 2020 - 04:40 PM.


#57 areyoukiddingme

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Posted 27 May 2020 - 04:38 PM

When I had my wisdom teeth out in 1989, for pre-surgery I was put in a room with another young man that was having his out.  At the time I weighed about 160 and the other kid weighed about 100lbs more than me.  
 

The doctor came in and told me it would take a lot to put me out because I was a redhead.  I thought he was joking but after the surgery he told me it took twice the anesthesia to put me out as that other kid that weighed 100lbs more than me.

 

There is research that backs that up.  So I’m not saying there is anything to this night vision thing, but there are unexpected correlations between genetic traits and things one would not expect.

Red heads hard to knock out. Noted :-)

 

I do think the idea that eye color and light sensitivity are associated is a viable hypothesis, that's why I'm following to see if there's any evidence.

 

I have a hypothesis about color vision and visual sensitivity in low light conditions.

 

My guess is that men with poor color vision may have a trade-off where they aren't good at differentiating colors, but they are good at spotting and tracking objects in low light conditions.

 

I'm speculating that this may have evolved to increase the ability to spot prey in low light conditions, which would have been especially useful for those looking for a tasty bunny rabbit in the depths of winter in northern regions.

 

Eye color may be another association. . . 

 

It would be a fun hypothesis to test, and I will probably get around to it one of these days.

 

Another interesting aspect, is tetrachromacy. About 12% of women have four cone cells, and can differentiate colors like crazy. They weren't discovered until they could be given tests sufficiently difficult.

 

There's a genetic association in there where I think the tetrachromatic females are likely to have color blind fathers.

 

My bet is that this is an interesting genetic complementarity where the females are specializing for detecting differences between edible and dangerous foods (say mushroom and various plants), whereas the males are specializing for detecting those bunny rabbits.


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#58 areyoukiddingme

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Posted 27 May 2020 - 04:40 PM

In addition to what I've already posted, here's more:

https://www.almanac....ing-in-the-dark

  "Night vision is often better among people with blue eyes."

"What is known from an “evidence based” perspective is that individuals with light eyes (blue) tend to be more light sensitive." 

Thanks for keeping on digging (I like Bob Berman's books). I just wish they would cite the studies!



#59 Jon Isaacs

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Posted 27 May 2020 - 04:53 PM

My eyes are blue. I do have a large dark adapted pupil which can be part of increased light sensitivity but I don't feel like my eyes are more sensitive than average.

 

Rather, just the opposite.

 

In this thread, sensitivity to low levels of light would seem to be unimportant since for an individual observer it's a constant.

 

In terms of transmission differences between eye colors, this would be a small factor compared to the differences possible in photo-chemical dark adaption mechanisms. These represent several orders of magnitude, 10,000, 100,000.

 

Jon



#60 RLK1

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Posted 27 May 2020 - 05:24 PM

My eyes are blue. I do have a large dark adapted pupil which can be part of increased light sensitivity but I don't feel like my eyes are more sensitive than average.

 

Rather, just the opposite.

 

In this thread, sensitivity to low levels of light would seem to be unimportant since for an individual observer it's a constant.

 

In terms of transmission differences between eye colors, this would be a small factor compared to the differences possible in photo-chemical dark adaption mechanisms. These represent several orders of magnitude, 10,000, 100,000.

 

Jon

"In this thread, sensitivity to low levels of light would seem to be unimportant since for an individual observer it's a constant." Specific to my post on my comparo results that's both yes and no. Yes as it refers to my own findings specific to me but no in the sense in that is why I stated, "your mileage may vary", meaning the variables I noted, including my vision (20/20), absence of corrective lenses, and my own eye color may not a applicable to another observer. 


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#61 Jon Isaacs

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Posted 27 May 2020 - 07:21 PM

In addition to what I've already posted, here's more:

https://www.almanac....ing-in-the-dark

  "Night vision is often better among people with blue eyes." https://www.nvisionc...ye-color-guide/

"What is known from an “evidence based” perspective is that individuals with light eyes (blue) tend to be more light sensitive." https://coavision.wo...ct-your-vision/

 

I looked at these three links, I did see the term "evidence based" but I didn't see any evidence. 

 

I'd expect there to be the results of actual studies the way there is for dark adapted pupil versus age.

 

https://pubmed.ncbi....h.gov/20506961/

 

In my own search, what I found was that light sensitivity seemed to refer to sensitivity to bright lights and not sensitivity in a dark environment.

 

Jon


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#62 areyoukiddingme

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Posted 27 May 2020 - 08:12 PM

That's what I'm seeing too. I'll keep digging in the scientific literature, but it is already quite clear that ophthalmologists and psycho-physicists aren't really that interested in comparing people with different eye colors, and when they do it is to look at functional issues, for the former, and general principles for the latter.


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#63 RLK1

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Posted 28 May 2020 - 12:44 PM

While I've already listed multiple links that are specific to the discussion, I'll add additional confounders. While the following relate to clinical applications in ophthalmology, and it should be noted that it's certainly not unusual to have conflicting results in such studies, four out of the seven studies summarized in the included table note blue eyes have larger dark adapted pupils:

https://www.liebertp...9/jop.2010.0061

Again, the above applies to clinical applications, like those noted by Jon Isaacs, and may not be indicative of an equivalent application at the eyepiece.

Along similar lines, but more specific to light transmission which is more applicable to our discussion, and although not necessarily indicative of perceived changes at an eyepiece, it does indicate significant transmission of light in blue eyes versus brown:

https://www.scienced...04269899190057C

So other than the links I've already noted in my previous posts, I believe the last one above shows the ability of the lighter colored iris to transmit more light than a darker colored one, albeit not desirable in terms of the potential for glare which has practical applications for driving at night, but may also be potentially useful at the eyepiece...



#64 Jon Isaacs

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Posted 28 May 2020 - 07:28 PM

RLK1:

 

Your first link concludes:

 

"Conclusions: Contrary to long-held beliefs, female patients and blue-eyed patients do not have larger DAPD. Digital color sensing is a useful technique for objectively describing iris color."

 

https://www.liebertp...9/jop.2010.0061

 

In any event dark adapted pupil diameter plays no role with exit pupils of 4 mm except unless someone has an unusually small DAPD.

 

The second link is about the Iris and the transmission of stray light. The light that we look at enters the eye through the pupil, not the Iris. The light entering through the Iris is stray light and reduces contrast. The dark pigmented Iris seems to better at controlling stray light.  But blue iris's are still quite good:

 

"For a light-blue eye effective transmission of the iris was 1% for red and 0.2% for green light....

For the dark-brown eyes of pigmented individuals transmission is lower by two orders of magnitude."

 

https://www.scienced...04269899190057C

 

Jon


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#65 RLK1

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Posted 28 May 2020 - 08:15 PM

RLK1:

 

Your first link concludes:

 

"Conclusions: Contrary to long-held beliefs, female patients and blue-eyed patients do not have larger DAPD. Digital color sensing is a useful technique for objectively describing iris color."

 

https://www.liebertp...9/jop.2010.0061

 

In any event dark adapted pupil diameter plays no role with exit pupils of 4 mm except unless someone has an unusually small DAPD.

 

The second link is about the Iris and the transmission of stray light. The light that we look at enters the eye through the pupil, not the Iris. The light entering through the Iris is stray light and reduces contrast. The dark pigmented Iris seems to better at controlling stray light.  But blue iris's are still quite good:

 

"For a light-blue eye effective transmission of the iris was 1% for red and 0.2% for green light....

For the dark-brown eyes of pigmented individuals transmission is lower by two orders of magnitude."

 

https://www.scienced...04269899190057C

 

Jon

Given the fact that you and your cohorts could not even find the studies in question, I'm not certain that you're in a position to critically appraise them. 

Of course I realize what the initial study concludes but, unlike you, I'm not cherry-picking it to seemingly prove a point. I'm noting the variance in the studies noted within the link, hence my comments regarding 4 out of the 7 studies noted with in the link, again a common finding especially in a clinical context. A systematic review of the literature and or a meta-analysis would probably be a better means of coming to an accurate conclusion.  

With regards to the second link, of course the eye "sees" the stray light entering the eye; it is seen as glare and that is why blue-eyed people, because of the greater amount of total light transmission entering their eyes, may encounter difficulty when encountering bright light while driving. Virtually every link I've read notes the latter as the potential downside of the increased sensitivity of lighter colored eyes in low light night time conditions, hence my inclusion of the link in question...  



#66 Jon Isaacs

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Posted 28 May 2020 - 09:10 PM

Given the fact that you and your cohorts could not even find the studies in question, I'm not certain that you're in a position to critically appraise them.

 

 

:scratchhead:

 

I've been involved in many scientific discussions on a professional level. It doesn't work that way..

 

You are the one who made the claim that all this was scientifically proven. As such, it's you're responsibility to support your claim. So far, I haven't seen any concrete evidence supporting the claim. 

 

Why you posted the link to the light scatter of the Iris I don't know, it doesn't seem relate to the transmission through the pupil.

 

In any event, this really has nothing to do with the topic of the best eyepieces for galaxies. The comparison of the 18 mm's is of interest through an 18 mm at F/4.5 is not an optimal exit pupil for galaxies, generally 1.5mm-2.5 works best for me.

 

A comparison with a 11 mm Ortho and the 11 mm Type 6 Nagler would be interesting but with such a narrow field, an 11 mm Ortho is not practical for a manually tracked mount and star hopping.

 

Jon


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#67 RLK1

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Posted 28 May 2020 - 09:40 PM

scratchhead2.gif

 

I've been involved in many scientific discussions on a professional level. It doesn't work that way..

 

You are the one who made the claim that all this was scientifically proven. As such, it's you're responsibility to support your claim. So far, I haven't seen any concrete evidence supporting the claim. 

 

Why you posted the link to the light scatter of the Iris I don't know, it doesn't seem relate to the transmission through the pupil.

 

In any event, this really has nothing to do with the topic of the best eyepieces for galaxies. The comparison of the 18 mm's is of interest through an 18 mm at F/4.5 is not an optimal exit pupil for galaxies, generally 1.5mm-2.5 works best for me.

 

A comparison with a 11 mm Ortho and the 11 mm Type 6 Nagler would be interesting but with such a narrow field, an 11 mm Ortho is not practical for a manually tracked mount and star hopping.

 

Jon

While I disagree with several of the above statements, I see we could go back and forth on this for awhile and I do agree that we've diverged from the topic of the thread so I'll conclude my argument on light sensitivity by reiterating the professional and expert opinion of the Brass eye center and an included second link, "How Eye Color Affects Vision. ... Lighter eyes, such as blue or green eyes, have less pigment in the iris, which leaves the iris more translucent and lets more light into the eye. This means that light-eyed people tend to have slightly better night vision than dark-eyed people.Sep 13, 2018" Brass Eye Center -

https://prezi.com/1t...-night-visions/

A 9mm/10mm eyepiece works well for me in my 16" F4.5 and I use a 9mm ES100 or my preferred 10mm Ethos. I haven't tried a comparo between my 9mm ES and my 9mm BGO but that one will likely not be a blinded assessment.

Note: Above link is active in post 52 in this thread.


Edited by RLK1, 28 May 2020 - 10:30 PM.


#68 Jon Isaacs

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Posted 28 May 2020 - 10:27 PM

How Eye Color Affects Vision. ... Lighter eyes, such as blue or green eyes, have less pigment in the iris, which leaves the iris more translucent and lets more light into the eye. This means that light-eyed people tend to have slightly better night vision than dark-eyed people.Sep 13, 2018" Brass Eye Center -

 

 

Please think about what you just wrote.

 

The exit pupil is smaller than the dark adapted pupil so the light from the telescope never reaches the iris.  

 

And even if it did reach the iris, which would imply the exit pupil is larger than the dark adapted pupil, the transmission is very poor:

 

"For a light-blue eye effective transmission of the iris was 1% for red and 0.2% for green light....

 

Jon



#69 areyoukiddingme

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Posted 28 May 2020 - 11:19 PM

While I disagree with several of the above statements, I see we could go back and forth on this for awhile and I do agree that we've diverged from the topic of the thread so I'll conclude my argument on light sensitivity by reiterating the professional and expert opinion of the Brass eye center and an included second link, "How Eye Color Affects Vision. ... Lighter eyes, such as blue or green eyes, have less pigment in the iris, which leaves the iris more translucent and lets more light into the eye. This means that light-eyed people tend to have slightly better night vision than dark-eyed people.Sep 13, 2018" Brass Eye Center -

https://prezi.com/1t...-night-visions/

A 9mm/10mm eyepiece works well for me in my 16" F4.5 and I use a 9mm ES100 or my preferred 10mm Ethos. I haven't tried a comparo between my 9mm ES and my 9mm BGO but that one will likely not be a blinded assessment.

Note: Above link is active in post 52 in this thread.

Would you mind checking this link? (I'm getting a 404 error).

 

I'm still interested in seeing if there's any evidence for differences in light sensitivity and and eye color (or indeed other variables). But I'm not coming up with much. I think I'll look at light sensitivity in general and work backwards.

 

I'm an academic and quite used to searching for scientific research. While this isn't my field, it's clear that work on this specific subject is not common.



#70 RLK1

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Posted 28 May 2020 - 11:49 PM

Would you mind checking this link? (I'm getting a 404 error).

 

I'm still interested in seeing if there's any evidence for differences in light sensitivity and and eye color (or indeed other variables). But I'm not coming up with much. I think I'll look at light sensitivity in general and work backwards.

 

I'm an academic and quite used to searching for scientific research. While this isn't my field, it's clear that work on this specific subject is not common.

I modified my last post to note the link is active in post 52 of this thread.



#71 RLK1

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Posted 29 May 2020 - 08:21 AM

Would you mind checking this link? (I'm getting a 404 error).

 

I'm still interested in seeing if there's any evidence for differences in light sensitivity and and eye color (or indeed other variables). But I'm not coming up with much. I think I'll look at light sensitivity in general and work backwards.

 

I'm an academic and quite used to searching for scientific research. While this isn't my field, it's clear that work on this specific subject is not common.

I modified my last post to note the link is active in post 52 of this thread.

You need to expand your key words and if you do, you'll uncover a slew of articles, pro and con, depending on your point of view on this discussion. I've touched on a few on them here. Like most articles on this topic, the subject matter is clinical and may be misinterpreted by a layperson. A few are related to military applications, ie night vision in a combat environment.  Enjoy your search, PM me if you have difficulties since we're off topic from the intent of the thread.


Edited by RLK1, 29 May 2020 - 12:57 PM.



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