Ways for Monsters to See in the Dark

[Daigoro]

Spore Vision?

The cave system is filled with a species of fungus that emits clouds of sticky spores when anything moves through. The fungus and the spores emit a particular wavelength or magical aura that the cave-dwellers' eyes are attuned to, allowing them to make out the shape of the terrain as well as see visitors who have been tagged. People tagged by the spores would need to have a thorough soaking or a Sterilise spell to become undetected again.

[thrash]

Something similar could be achieved with vibratory sensors and the Preparation Required limitation -- e.g., spider webs that not only transfer vibrations in the air to a tactile receptor, but provide specific feedback when brushed against.

[Willy]

Ha someone in this threat already mentioned trap door spiders and their hunting method? They hav ea system of silk strands around their hiding place, if anything stepping on that strands the spiders gets the info when were and how big, sometimes this system is big enough to have a 1 meter diameter, quite far away from the hiding place. A mostly sessile cave living creature could use such a trick.

[The Colonel]

UV works for warm blooded critters though doesn't it? I recall mentions of "ultravision" in AD&D, but it seems to have gone down the memory hole...

[Fred Brackin]

Originally Posted by The Colonel

UV works for warm blooded critters though doesn't it? I recall mentions of "ultravision" in AD&D, but it seems to have gone down the memory hole...

Some birds (along with some insects) can see slightly beyond the upper limit of visible light. I think it's 260 nanometers v.350 for us and most other creatures. Some flowers have pigments in this range.

The required adaptation is a different type of rod/cone. No cooling or other exotica is required. The near UV photons have plenty of energy.

[Willy]

Originally Posted by Fred Brackin

Some birds (along with some insects) can see slightly beyond the upper limit of visible light. I think it's 260 nanometers v.350 for us and most other creatures. Some flowers have pigments in this range.

The required adaptation is a different type of rod/cone. No cooling or other exotica is required. The near UV photons have plenty of energy.

Also some plants and insects have spots that can only be seen in the UV spectrum, so insects or at least pollinating insects can see part of the UV spectrum.

[Anthony]

Originally Posted by The Colonel

UV works for warm blooded critters though doesn't it?

It does, it's just that (GURPS and AD&D rules notwithstanding) it's almost totally useless for seeing in the dark. The only way you have an area well illuminated by UV that isn't also well illuminated by visible light is if you're using a UV lamp (and depending on the area, that might still permit vision by normal light -- UV causes a lot of things to fluoresce).

[Farmer]

Originally Posted by Fred Brackin

Some birds (along with some insects) can see slightly beyond the upper limit of visible light. I think it's 260 nanometers v.350 for us and most other creatures. Some flowers have pigments in this range.

The required adaptation is a different type of rod/cone. No cooling or other exotica is required. The near UV photons have plenty of energy.

Some humans are also tetrachromats - it's rare, and mostly in women. It still requires an illuminant, of course.

I strikes me there are two reasons for creatures to see in the dark. Firstly, because of a lack of natural light - they develop other senses or very sensitive vision or adapted vision to cater for the available wavelengths and intensity and their requirements. In such cases, most creatures in that environment will have a method of dealing with it and, like with normal vision, it will vary to suit their evolution.

The second would be to gain an advantage over other creatures. This is where some sort of self originating illuminant in an "exotic" wavelength light occur, such as IR or UV, or even things similar to millimeter radar (para-radar, anyone?). Whilst this could eventually be evolved in other creatures as a response, the first creature to develop it would have a significant advantage potentially.

So if you're looking for "science" ways to have dark vision, consider self originating illumination in exotic frequencies that humans don't have but might be able to detect once they figure out what's going on.

[Fred Brackin]

Originally Posted by Farmer

Some humans are also tetrachromats - it's rare, and mostly in women. It still requires an illuminant, of course.

It's nothing to do with UV either. The extra color is a variant of green. See Enhanced Senses.

[Farmer]

Originally Posted by Fred Brackin

It's nothing to do with UV either. The extra color is a variant of green. See Enhanced Senses.

Tetrachromacy in humans cold never see into the UV spectrum because our eye lens blocks most of the light in the 300–400 nm range (we can start to see at about 380 nm typically) and the cornea blocks shorter wave lengths.

Other species of tetrachromats, however, can see into the UV spectrum.

Studies vary on what human tetrachromats can see, but the 4th cone seems to be sensitive between the standard and red and green cones, and some others seem to just have increased discrimination across most of the normal visible spectrum for humans.