#snake vision

[ziskeyt]

The snake that ate up 80% of my vision in my left eye yesterday. We decided his name was Jorge. He left after a few hours. Know that he was no static colour he was every colour in vibrant light flickering constantly and jittering about slightly in my sight.

[clairedelune-13]

I just realized something kinda sad.

Remember when Crowley was an Angel, who created that beautiful nebula, with all the FANTASTIC COLORS?

But then, he fell and became a demon.

A snake demon.

With yellow pupils.

Which means he probably has dichromatic vision, making him only able to see various shades of green and blue.

Colors barely and not available in his precious nebula.

So, while he could see his work if he wanted to; it wouldn’t be the “pinky blue bits” - the blue, but certainly not the pink portions - Aziraphale loved so much. So, more like…greeny-blue, I guess?

Not terrible, but not their true colors. Not Aziraphale’s favorite. The bits Crowley’s no doubt most proud of.

Anyway, just thought of this. Bye.

[pleasespellchimerical]

So one thing that my Master’s degree has impressed upon me is a super intense curiosity regarding animal vision.

Thus: Good Omens meta time, starring snake vision!

Cursory google searching tells me that snake vision varies considerably by species and habits. But there are commonalities that we can pick out!

First: Pupil shape. Snakes with round pupils tend to be diurnal, snakes with slitted pupils tend to be nocturnal. Vertical slit pupils are thought to exclude light better than round, and have a greater dynamic range. 

Second: Spectral sensitivity. Most snakes have blue/green sensitivity, as well as UV sensitivity. Because excess UV light during the day could damage the eye, diurnal snakes tend to have a yellow lens over their eye that excludes UV light. This often results in diurnal snakes having yellow, gold, or amber eyes because the lens extends over the whole eye.

(Human lenses are yellowed as well, for the same purpose. However, the human crystalline lens is inside the eye, which means it doesn’t affect our eye color).

Nocturnal snakes have eyes that do not exclude UV light. Adding this on top of the slit pupil, this means that nocturnal snakes probably have very good night vision. (Some UV light does exist at night--sunlight reflected off the moon).

So what can we assume about one demon with snake eyes?

Crowley probably has very good night vision! I’d be more hesitant about specifying a complete spectral sensitivity--he might be red colorblind like some humans, or he may have RGB sensitivity plus UV. Snake-featured eyes with a more human retinal structure and nervous system--who knows, man.

But there’s another thing here. The sunglasses. If he’s sensitive to UV light, then the sunglasses may serve a very practical purpose (besides not freaking humans out and emotional defense mechanism). Daylight might hurt a lot!

Which means that he’s only visually comfortable taking them off in dim spaces without much UV light, such as the backroom of Aziraphale’s shop. 

Source:

https://www.nhm.ac.uk/discover/news/2016/september/study-sheds-light-on-snake-vision.html

(The first few results on google for ‘snake vision’ all summarize the same study, which examined ~70 species and was published in 2016)