There was a report on the BBC website,
http://www.bbc.co.uk/news/science-environment-31775458, that there appear to be tubes that direct red and green light to the red and green cones on the retina, with blue light being scattered more and reach the rod cells as well as the blue cones.
My question is, if our sun was not a yellow star, but was blue, for example, what affect on the vision of any life form that inhabited this hypothetical earth would there be?
Also, certain life forms, for example insects have a higher sensitivity to the blue end of the spectrum than humans do, is this because their eyes evolved when the Sun was younger and hence had a higher output in the blue/UV end of the spectrum?