Lined and hardened, as though by exposure and want of personal care, there was also a lack of sensibility, an almost animal callousness, on the coldly lit eyes and unflinching mouth, which readily suggested some terrible and recent experience--something potent enough to have dried up the human nature out of the man and left him soulless.
Eye colors depend on the amount of pigment (melanin) found in the iris and how it is distributed. Light gray-blue eyes contain much less pigment than extremely dark brown eyes. And there are many shades of eye color in between.
This implies that there are more people on earth with brown eyes than all the other eye colors combined. So, even though it is hard to find reliable statistics on the distribution on eye colors, one can still say with confidence that brown is the most common eye color in the world.