Do LED's affect your night vision less?

[Ming65]

I underestimated the time on a bush walk last night and did the last 3 hours in the dark. Had my princeton tech aurora with me and I was familiar with the terrain so no problems. There was just a tiny sliver of moon showing so I decided to switch off the light and sat to wait the 10-15 minutes for my night vision to come on. It suprised me that I had good night vision almost straight away. I was wonderng if anybody else had experienced this?

I also notice that the dog's eyes reflect blue instead of red/orange in the dark so I'm sure the LED's are a different type of light. I'm going to go out with my old Pezl and compare how they both effect night vision in the next few weeks but was wondering if anybody else had had some experience with this.

 

[pjenkins00]

i dunno but this site:

http://flashlightreviews.home.att.net/qa.htm

has lots of good info on stuff like that and might help you figure it out.

by the way i like your signature. always seems so close....

Pete

 

[golok]

I haven't really thought about it but now that you have mentioned it, yes. It affects my vision less. And my flashlight is a six-headed hydra!

 

[HJK]

Both colour and intensity can have an effect on your night vision. That's why you turn down the dashboard lights in your car and they, and some streetlights, are yellow or orange.

 

[UnknownVT]

True human (eyes) "Night Vision" is Scotopic (rods only) vision - which takes several minutes to adapt. One can see in what normally would be called "pitch black" - one does NOT see in color, the vision is pretty blurry and a lot of people are uncomfortable with it.

Most people's normal eye dark adaption is probably not Scotopic - since we mostly are in urban environments and there is always some light (pollution).

In the case of seeing by moonlight - that definitely is not true scotopic night vision, especially if one can see detail fairly well.

To preserve true scotopic night vision - red (above 650nm wavelength) is the correct color to use since the rods are insensitive to that light and the eyes' cones can see by that color light. However it still needs to be dim level - otherwise the cones will be flooded and the after-images will blind one's night vision.

Also some people have trouble seeing definition well under red light especially with the onset of "old-sight"

To preserve normal (non-true scotopic) dark adaption - it is much more a function of the dimmness of the light - there are color preferences - but none have been conclusively shown to be at an advantage - I personally like yellow/amber - as I seem to see well - good definition and contrast by low levels of yellow - which in turn helps preserve my dark adaption.

There's a good thread at CandlePowerForums

Human Night Vision Preservation

 

[Ming65]

Excellent, thanks team.

 

[Moine]

Originally posted by Ming65
I decided to switch off the light and sat to wait the 10-15 minutes for my night vision to come on. It suprised me that I had good night vision almost straight away. I was wonderng if anybody else had experienced this?

Most probably anyone who has tried...!

I'm an (armchair) anthropologist. I've been studying bit on those matters, since many of our ancestors and mainly prehistorical hunters were (apparently) very active at night. They were probably able to hunt down preys even on the darkest nights, but that's something that needs some practice.

Unlike most people seem to believe, we, humans, DO have a good night vision. The main problem is that this vision is not as acute and clear as the one were are used to. It's color-blind, and not good at seeing small details, but rather gross and sensitive to movement. Besides, we see better with our peripheral vision in the night (because the part of the retina that is responsible for peripheral vision is covered with rods, and not cones).

When on "night vision mode", one must not try to see details, but rather concentrate on a "wide angle" mode. Expand your vision instead of trying harder to focus on things. To see something better, don't look straight at it, but rather use your near-peripheral zone. Don't force it. Just accept this new vision mode.

After a few weeks of being active in darkness, you eye slowly adapts and develops it's real potency for night vision. Some connections take place neurologically (essentially, the bipolar cells that connects the light-sensitive neurons [the famous rods and cones] between them and eventually to the optical nerve develop more connections, thus letting the "signal" travel better), and you end up seeing better and better each night, until you reach a final plateau (typically after 6-8 weeks, if my memory serves).

A lack in Vitamin A can cause a bad night vision, but it's not possible to boost your night vision by taking lots of it (this would only give you headaches and might eventually be lethal).

Any mistake in this post is the result of my very own idiocy.

Best regards,

David

 

[Ming65]

Thanks David,

The awareness issue is something I hadn't thought of. A standard bulb tends to concenrate a brighter light in a smaller place whereas a LED has a more spread, diffuse beam. This may create a smaller adjustment in awareness when switching the light off.