Quote Originally Posted by spudz11
wow.. just found a very interesting article

http://jeb.biologists.org/cgi/reprint/202/14/1931.pdf

so... the BP's have rods and 2 types of cones. The rods peak in sensitivity around 494nm wavelength, which corresponds to a blue-cyan color. But, since they are rods, this is won't be perceived as color to the snake, only brightness.

The most abundant type of cone is sensitive to a peak at 551nm, which is between green and yellow, but closer to yellow. The other type of cone is apparent in fewer numbers but has peak sensitivity at 360nm, smack in the middle of the UVA spectrum. In the article, the authors speculate that the UV sensitive cone, which there is almost none in the retina, may contribute to pheromone detection.

Keep in mind that although the sensitivity peaks at these noted wavelengths, sensitivity occurs at both higher and lower wavelengths. The activation of the cones and rods will decrease in a bell shape fashion falling off form the peak value and decreasing to zero activation at wavelengths adequately different from the peak. To give an example, the human 'red' cone is peak responsive at 560, but will respond slightly all the way to about 605nm and as low as 470. All of the human cones have a sharper drop off at higher wavelengths than lower wavelengths.

Since, reddish color starts at about 600nm and goes until about 700nm or so, the snake will not see much at all, if anything. So, its good for nothing but heat... and as you say 25 watts isn't going to do much for heat... so save your money on electricity and don't use it. perhaps a more appropriate night light would be an extremely low wattage moon light bulb, which provides a dark blueish glow, i believe zoomed makes one.

So, I may provide an interesting argument that it may indeed be beneficial for snakes to have a light that produces UVA, not for vitamin D production.. but for sustaining the proper vision. Further, breeders may want to consider this too if it has the potential to facilitate and strengthen the mating processes. For those who want to try, keep in mind that the snakes you've had as breeders for a while may no longer be sensitive to UVA, since areas of the brain that are not stimulated during development will atrophy or develop to be associated with other brain functions... but plasticity of neural systems may allow the cones may to regain a visual function, yet not necessarily allow them to be received by the areas associated with reproductive behavior. So, if you're going to try it, raise one of your breeding snakes from day 1 on UVA light in addition our visual spectrum.

-Brian

Thanks for that... Yeah I'm not using the bulb for heat, I'm using it to see the snake at night and not bother him with white light.