Which learning tasks do brains use to train themselves to see?
Maybe this paper will give you an overview about (and entrance to) this topic from biological side. It is a review about the state of the art in human brain development (and its implications for clinical treatment).

The table of contents include for example


Stage 1: the first year, early maturation of vision and the structure of V1 neurobiology
Stage 2: preschool children have high variability in V1 development (1–4 years)
Stage 3: experience-dependent visual development in school aged children (5–11 years)


(V1 means "visual cortex")
Where this points all handle 3 categories: visual milestones (i.e. contrast sensitivity, contour integration), anatomical milestones (i.e. morphology) and neurobiological milestones (i.e. synapsis, but also a lot of genetics).

And as second : Maybe you could ask this question on bioinformatics.SE too, because this connection between biological example and computational reproduction is one of their fields.