How do fish view light?

[JamisonBWolsh]

As we all know, not every living creature views the world as we do.

My question is:

How does fish visualize light?

Example: some people say fish does not see the red light and its dark as night with that color.

some other people say..no thats not true... The red light is Bright as daylight to them.
what about Blue? do they register it as a color? or do they visualize it just as a dimmer light, like that of the strip light (white) ? Thanks

[carpguy]

Fish is a broad category. Its probably a more general question then "How do mammals see light?", when we all know that dogs and cats are not seeing things in the same spectrum we are. Understanding Tropical Fish has an interesting section on fish vision that touches a little bit on color. The nutshell version:

Different fish see different things. Fish that live at moderate depths are going to be exposed to much bluer lights and may not bother developing full-spectrum vision. Deep water fish may not bother with color vision at all. Nocturnal bottom dwellers probably don't have great color vision, so catfish probably don't see red light. Diurnal surface feeders probably do have good color vision and may find the red lights just as visible as you or I.

[Serrateeth_2002]

Red light don't penetrate water as much as other colours i think,maybe that's why they aren't evolved to see red,i could be wrong,do fish have red colour or light receptors in their eyes?Other than that,some fish are blind,some use smell,BGKs are considered blind but do they live in caves and sort?Most fishes use the sense of smell more than sight so sight is not one of their main senses like touch and smell.