men and women see things differently

Dr. Israel Abramov et al had published 2 interesting studies showing men and women had differences on how they see the world.

Abramov, I., J. Gordon, O. Feldman and A. Chavarga. "Sex and Vision I: Spatio-temporal Resolution."
Cerebral cortex has a very large number of testosterone receptors, which could be a basis for sex differences in sensory functions. For example, audition has clear sex differences, which are related to serum testosterone levels. Of all major sensory systems only vision has not been examined for sex differences, which is surprising because occipital lobe (primary visual projection area) may have the highest density of testosterone receptors in the cortex. We have examined a basic visual function: spatial and temporal pattern resolution and acuity.

Abramov, I., J. Gordon, O. Feldman and A. Chavarga. "Sex and Vision II: Color Appearance of Monochromatic Lights."
Because cerebral cortex has a very large number of testosterone receptors, we examined the possible sex differences in color appearance of monochromatic lights across the visible spectrum. There is a history of men and women perceiving color differently. However, all of these studies deal with higher cognitive functions which may be culture-biased. We study basic visual functions, such as color appearance, without reference to any objects. We present here a detailed analysis of sex differences in primary chromatic sensations.

If you plan to design usability studies, please take into account those discoveries.