Merry Christmas to me.

[Mr.Silver]

The red light is for deer hunting and turkey hunting when walking thru the woods in the early morning it does not scare game away with a bright light I use a green light around my cap in the morning when I go deer hunting like tomorrow morning I got it from Radio Shack® 15 years ago, its light it runs on 2-AA batteries made velco strap around headband, becuase thru the years the elastic got bad!!!

Mr.Silver

[FinalLastDays]

Red light preserves night vision. Rhodopsin is defined as a pigment of the retina that is responsible for both the formation of the photoreceptor cells and the first events in the perception of light. It is the chemical that allows night vision, and is extremely sensitive to light. Exposed to white light, the pigment immediately bleaches, and it takes about 30 minutes to regenerate in humans.
I use red lights constantly for my other hobby of astronomy. My astronomy computer programs have an option that lets me put the screen on all red when I have them hooked to the telescopes. It is a constant battle, especially in urban areas, that light pollution hinders what one can view of the night sky. Many times, during star parties, they make aware to the public the importance of light pollution. Do this test... go outside on a clear night and look up at the stars... remaining in darkness without any "white" light (cars, houselights, cell phones, etc.) look up a few minutes later... notice there are more stars... do this for a few more minutes... notice there are even more stars now. Now subject yourself to "white" light again and look up... those stars are now down in number again, at least to your perception of them.

As for the baseball cap with LED lights, I have seen them at Sears, and they do have both the white and red LED's on them... I considered purchasing it for metal detecting before I purchased the "head light" from Harbor Freight. If I were to use the hat for MDing, I personally would use the white lights, however I would use the red if I were to use the same hat for astronomy.

[JoAnne]

Thanks for all the replies. I was not sure why I would need red lights. I think I may go to Sears and see if they have the hat that was mentioned. Heck you can never have too many lighted hats.