James Dreben 
#ELI5 Why is water see through?
I'd never thought about it like this. Wow.
Jacob Christian Munch-Andersen@Jdreben That is true, but it is not the only condition that has to be met for a wavelength to be suitable for sight. First of all for sea creatures to see light it has to be emitted by the sun, pass through the atmosphere, and pass through the water. Then it also has to be blocked and/or reflected by relevant objects in order to be useful.
@Jdreben There is also the issue of how the sensor is implemented. For instance infrared vision would be extremely useful for us above-sea creatures. But our own bodies produce infrared because they are warm, which makes it hard to filter out the relevant signal. Maybe there is a solution for infrared, but AFAIK evolution hasn't found it yet.