For the optic nerves in humans, a similar questiom comes -- Why does it connect to the rear side of the brain when the front is much closer! This perhaps relates animals having their eyes on the sides of the head and a relatively small brain positioned in a way that the eyes were closer to the rear side of the brain.
I'm far from an evolutionary biologist but AFAIK the majority of our brain is a late addition in the scheme of our evolution from sludge to human and vision is connected to one of the older parts and the new parts are up towards the front. Another case of the iterative nature of evolution, the frontal cortex where most emotion processing happens came about and enlarged a lot through the evolution of chimps that eventually branched off into humans.
For the optic nerves in humans, a similar questiom comes -- Why does it connect to the rear side of the brain when the front is much closer! This perhaps relates animals having their eyes on the sides of the head and a relatively small brain positioned in a way that the eyes were closer to the rear side of the brain.