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51

This is the four-eyed fish: It has only two eyes, but it two pupils and two retinas in esch. It evolved to hunt by the water surface, catching prey from both above and below. Where there is an evolutionary pressure, there is a way to evolve. This fish proves that what you want is possible. However, do notice that this fish evolved multiple pupils because ...


26

It may interest you to know that some of the earliest animals on earth were largely invisible to night vision goggles in the first place, and that later animals have actually evolved to be visible in night vision. The secret, as it turns out, is to be cold blooded. We'll get to that, but first let's deal with camouflage... To begin, we have to understand ...


14

Yes, it is perfectly possible for dichromats to see red wavelengths. The number of distinct receptor types has essentially nothing to do with the range covered by those receptors. Even in the specific case of dogs and cats, I'm reasonably certain they are still sensitive to red wavelengths--they merely lack the ability to distinguish them from green.


10

Infrared, Sonar, and Other Waves Some animals use "bio sonar", or echolocation as a form of "sight" (ie, navigating and foraging). It's also possible for your creatures to see infrared radiation. If fact, your creatures could emit small amounts of waves from just about anywhere on the electromagnetic spectrum, except for visible light, and therefore "see" ...


10

There is no problem. Don't get bogged down by trying to imagine "how the world looks" to such a creature. In the real world, there are all kinds of animals with all kinds of senses coming from all kinds of angles and it just works, because brains are flexible and don't really care where their information is coming from or what form it takes, as long as it ...


9

Just think of that other place where the sun doesn't shine. I mean the ocean depths. The bioluminescence of a blind animal (such as a bioluminescent jellyfish) can either stun or confuse a predator that is not blind. The atolla jellyfish in particular is a sore loser - if it gets attacked by a predator that is able to eat it, it gets flashy and its lights ...


6

It can be an illusion Many mammals have (the illusion of) glowing yellow eyes - deer, dogs, racoons, etc. I say "illusion" because the eyes themselves are not emitting the light, but reflecting the light. You can think of this something like someone with bleach-white teeth in a dimly-lit room. If the light hits it right, the contrast between that much ...


6

KISS! (Keep it Simply Stupid) One pupil per eye, multiple eyes because multi-pupiled eyes would become a nightmare from an optical design perspective: The pictures you posted are about the exterior of the eye but the interior is what makes it work, and there is no biological advantage in multi-pupiled eyes as you'd need multiple lenses, irises, ciliary ...


6

Cats and dogs can see red light just fine. What they cannot do is distinguish it from green light. At the red end of the visual spectrum their limit is very similar to the humans, extending to about 750 nm. But at the blue end of the spectrum they may see quite a bit into what for us is invisible near ultraviolet, because their lenses absorb ultraviolet ...


5

Yes. Modern mammals lost two different color receptors (cone cell types) to make room for more rods in the eye, to get better night vision. you can easily have the same thing happen. Mammals lost the UV and green receptor, most importantly without the UV receptor we can't see that end of the spectrum at all, if the blue receptor was lost as well we would ...


4

Not a biologist or physicist, but the simplest answer I can think of is infrared vision. https://www.youtube.com/watch?v=Y7mROTPAVZM As seen here, it does penetrate fog to a degree, and at long distance. Yes, infrared isn't as clear as normal vision without fog, but it is probably enough of an advantage in bad conditions to be viable. I think you can ...


4

The chemicals that create bioluminescence in animals are often highly toxic. This could be a warning to predators, which is how it is often used in nature for terrestrial creatures, or a part of its hunting strategy. If the frill is spikey, like the quills of a porcupine, it could use them to poison and kill its prey. Obviously, the creature itself would ...


4

Bioluminescent pets Anglerfish come to mind. There is evidence that giant squid are bioluminescent and that they use flashes to stun and catch prey. You may also consider for a really heavy metal factor, specially pirate metal. Suggested theme song: Leviathan, from Alestorm.


4

Light wavelengths double as they enter my eyes. Visible light becomes infrared, UVA becomes red, UVC becomes blue. What does the world look like to me? You won't be seeing that much. The transmission spectrum of our atmosphere has several hills and valleys. Our window of 380-740 nm will become for your eyes 190-370 nm. As you can see from the ...


4

Is yellow bioluminescence a thing? Yeah, look at Firefly How do the eyes work without pupils? It does not, without hole in iris no light would came to eye. In case you meant absence of iris, it can work, but you lose ability to accommodate to different light insensitivity, situation when someone don't have it is called Anidrida, look it up. Doesn't the ...


3

One possibility is has been answered already, for various reasons related to evolution in a low light environment. Another possibility is similar to an astronaut's visor: The eyes may have evolved a reflective sheen to reduce the incoming light. Ideally this would adjust for lighting conditions the same way the iris would contract or expand. In this ...


3

[Would a dichromat] necessarily not be able to detect large light wavelengths (red)? I would much rather them not being able to detect small (blue) instead, and have a similar vision to tritanopia. Is that possible? Possible? I don't see why not. AFAIU, the three flavors of human color blindness are caused by a lack of one of the three usual types of cones....


3

An option that others have not mentioned... Consider a creature whose vision works well down in the infrared (effectively 'seeing' heat), or well up into the ultraviolet (the way some insect eyes do). In that case, a yellow glow would not interfere with its vision, because yellow is out of its visual range, and pupils might not be recognizable as such ...


3

Not all animals who live in the cave or who live nearby may not be completely blind like your creature. Maybe there are others who use very acute vision, who could see well with tiny amount of light. Or maybe they have their own sources of light, like the Angler fish which helps them see inside the dark caves. So while your creature is visually blind, it ...


3

The bioluminescence can be a vestige of when the creature's ancestors lived in very dim caves or caves (or other spaces) that were dark part of the time while they were awake. While they still had functional eyesight. Plenty of species have biological traits that aren't currently needed. If there's no evolutionary advantage to not having them, they may ...


3

The Mantis Shrimp (certainly a fast predator on some scale) has triple-sectioned compound eyes (each section having a pseudopupil, as others have called out on different animals' compound eyes), and the eyes are very movable on stalks. While this doesn't optically equal the idea you've asked about, the complexity and distinct functionality of the separate ...


2

Yes The non-TL;DR version: It all comes down to photoreceptors Better night vision can be a mix of several things: foveal acuity, tapetum lucidum, and available visual spectrum are the ones that easily come to mind. Foveal acuity could easily be selected for, whether naturally or through selective breeding. The tapetum lucidum assists night vision via ...


2

If you will, let's start with some pseudo-biology. We see three colors because we have photoreceptor cells filled with color pigments (red, green, blue) which, when excited, send signals to our brain to be processed as information. The visual signals that are theoretically possible are not limited to these three wavelengths of Electromagnetic radiation (...


2

The human eye is very optimized to do what it does and that is detect various levels of light that you might find throughout the daytime; essentially dusk till dawn (pun intended). The frequencies that are eyes detect (visible spectra of colours) are not random either and are very in tune with sensing relevant information about the world which aids in ...


1

The only thing I know that has the power to do that today is machine learning, meaning by doing an excellent prediction. You could make an analogy between deep learning and high sensitivity. Deep learning prediction is based on learning from slight variation in data in a very complexe way. The ability to make several layers of opaque solid objects ...


1

They are not the real eyes Eyes need a pupil to see, and that pupil must absorb light, meaning it will be black. But that doesn't mean you can't have a creature that looks like it has glowing eyes. Exhibit A, the flashlightfish: Looks an awful lot like pupil-less glowing eyes, doesn't it? But the glowing organs are not the real eyes. The real eyes are the ...


1

Why would it evolve glowing eyes in the first place? These creatures are social animals like us. Things that set off the eye against the face are attractive. https://www.marieclaire.com/beauty/makeup/a134/smoky-eyes/ How do the eyes work without pupils? They do have pupils. The pupils are big. The entire visible eye is the enormous pupil. The rest ...


1

Cat's eyes glow because they have a layer of reflective material at the back of the eye. This causes any light that gets to the back of the eye to reflect forward. This gives the retina a second chance at detecting any given light, and makes the retina effectively much more sensitive. You see light reflected back, and so light coming from the eyes like a ...


1

So why would it evolve something like that? Because it evolved the frill before it became a completely subterranean species. Additional thoughts/uses: The frill is an echolocation receiver (it helps capture the reflected sound waves). It's a mating display, possibly with the bio-luminescent spots "looking" different to echolocation than the surrounding ...


1

Long wavelength EM or sonar are both probably good picks for low-latency feedback. However, both types of wave will be scattered and attenuated to some extent (just, less so than visible light EM). One thing to note is that "Temperature and humidity affect odor because they increase molecular volatility." Perhaps your Hell Fires have extremely sensitive ...


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