A just so story for you. Historically male primates of the genus homo have been hunters, often operating on terrain with features at various depths passed thro

A just so story for you. Historically male primates of the genus homo have been hunters, often operating on terrain with features at various depths passed through on the go. To construct an accurate representation of the the natural world and the relative distances of objects it would thus be beneficial for the male retina to spend more resources processing depth cues that arise from motion parallax compared to women for who survival may not have depended on being able to accurately discern distances of game moving through brush. This story is just that, a story. But the biology underlying sexual dimorphism of the visual system is definitely real and the fact that a sex hormone is involved may not be surprising since if, for example, an androgen receptor is expressed in a certain cell type in the retina and that cell type is in the circuit for parallax depth perception and that receptor enhances the response to differential parallax by say, depolarizing that specific cell type, then only males will have that enhancement.