Tom,

Could you amplify on your techniques for improving vision at night. I'm suspect I could improve mine (brown-eyed) a lot. That (brown-eyed) also applies to my family and most of my troop.

Thanks,

John

I recall reading that at the outset of WWII it was a common misconception among US troops that the Japanese were lousy night fighters because they were brown-eyed. That was disproved in a hurry. I think this brown vs. blue eyed business may be more myth than fact but I too would like to see hard evidence one way or another.

Regards, Vince

I agree on the myth part. Night vision depends on the retinal rods mostly so peripheral vision must be intact. The color of ones iris makes no difference.

Thinking along the lines of "improving night vision", (sensory inforamtion); I know you can improve your hearing capabilities. I wonder if you can also do this with your vision?

For those of you who, as an example, have small children that you were responsible for at night...think of how you were able to detect that child's smallest sounds...even when you were asleep.

I always thought of it as "hearing between the layers". Your brain learns to isolate the sound it needs to hear even when you are not consciously listening. I realize that a sleeping person will recognize a sound long before their vision would know start detecting anything.

Besides detecting form and movement in the dark; what other ways have any of you sharpened your night vision capabilities?

Do you depend on sounds around you as much as what you are able to see?

Naysayers: OK, I fully agree that it may be myth, but I offer a challenge: Prove it is a myth.

I "knew" this long before 1992. So far all I find on the www are statements similar to the one I made. That's not proof that it is true. But so far I find no clinical evidence one way or another.

As I wrote, my observations to date match the "common knowledge", and purposefully using night vision, purposefully teaching people to use night vision more effectively for over 30 years is at least a little bigger data set to draw on than simply guessing how well my own two eyeballs work vs someone else's eyeballs. But even that is not scientific; it's annecdotal.

Of course eye color per se has nothing to do with night vision! Is there a connection between eye color and number, distribution, efficacy, etc of rods? That is entirely possible - the question is, is it true or not in a general (meaningful) way?

I'll look for hard data because I made the statement.

But saying "it's a myth" with no supporting data is... well, prove it, OK? If we can find a truthful & definitive answer to the question, mission accomplished, whatever the answer is. I'd like to know myself - is what I said accurate or not?

I'm not flaming anyone, just pointing out that absent conclusive evidence, calling it "a myth" is the same as saying "it's true". I'm not married to the idea either way; I'd like to know the truth.

Regards,

Tom

I also agree about the myth part. In a healthy human looking at the structure of the eye (excluding the optic nerve) I can think of two factors that affect night vision capabilities:

the ratio of cone to rod cells (rod cells make you see at night). Both of which are part of the retina.

The effectiveness of the rod cells to "absorb" the light and stimulate the bipolar cells.

Other smaller factors that might be included is the distance between the rod cells and the fovea (centre of the retina where the light is focused on) and the ability of the iris to dilate, letting through more light.

Reinhardt

AyersGT,
You posted while I was typing mine therefore it's not in response to yours.

However I can see where you're coming from. That eye colour indirectly affects the ability of a person to see at night. I.e. the allele that codes for blue also affect the quantity/distribution/quantity of rod cells. Very interested in reading any evidence that comes to light for or against.

I just called an ophthamologist friend and he has never heard that either eye color has better visual acuity. Most of the websites I see say blue/green eyes have better night vision, which I do not believe either.

I looked for axactly what you were talking about: genetic cross-linkage of eye color (which is geneticly very predictable) with density of cones and/or ratio of rods vs. cones in the optic nerve array.

If it's out there, it will have to peiced together at a full-blown medical library. MedLine didn't get me anywhere.

HOWEVER: I did run onto a couple of items of interest:

http://www.nlm.nih.gov/medlineplus/drinkingwater.html

Compemndium of everything you ever wanted to know about drinkingwater. Note especially the section on "Emergency Disinfection of Drinking Water."

Poor Tom... you really know how to open a can of worms, don't ya? <img src="/images/graemlins/blush.gif" alt="" /> <img src="/images/graemlins/grin.gif" alt="" /> <img src="/images/graemlins/wink.gif" alt="" />