The epicanthic fold is a skin fold of the upper eyelid that gives a large percentage of the world, including many East Asians, almond shaped eyes, in comparison to Caucasians’ (although given the relatively minute percentage of Caucasians in the world, it may be better to note how many Caucasians lack epicanthic folds).  It is hypothesized that the epicanthic fold is evolutionary as it protects the eyes from harsh UV rays, strong wind, and frigid temperatures.  To compensate for the lack of epicanthic fold, I have to wear mirrored goggles around all the time.