Check the diagram and you’ll notice that each of our eyes is cleverly
“wired” to send the left visual field to our right brain hemisphere; and
vice-versa, right-side information is channeled to the left hemisphere.
Even if we were to lose one eye, our brain would still make this distinction.
In the previous test you chose face B as happiest.
About 30% of people taking this test choose face B. This suggests that you use your left-hemisphere for judging facial expressions. Notice that you favoured the right-side smile of face B.
You may be left-handed. About 60% of left-handers choose face B in this exercise. Left-handers typically have language abilities in their right hemisphere and facial evaluation in their left.
This is not just biologically interesting,
there are practical consequences.