How Orkhs see, and how to krunch it im GURPS

[Snargash Moonclaw]

true there - infrared is a good example - I wonder though about UV florescence - permanent blacklight poster world. . . There are a lot of natural substances that fluoresce under UV (the rocks & minerals section of most Museums of Natural History will have a decent display of this) while still displaying their visible colors, this just gets washed out by visible light, so can only be seen in a darkened room - this effect would probably be noticeable in broad daylight if you could see the light which causes it. For an interesting optical effect try wearing polarized (clear) safety goggles/glasses over polarized prescription lenses and look at the weird 3-D hallucinations this creates upon the surface a regular black asphalt street in afternoon sunlight.