Yes as the article staes, most people are not aware of the fact that iris pigmentation is based completely on the AMOUNT of iris pigment, not its inherent coloration.
Swedes for example simply have less iris pigment for example than Africans.
The presence of pigment throughout the eye, does have some beneficial, protective effects for other ocular pathology, such as age-related macular degneration (ARMD).
That’s interesting. My FIL (very blue eyes) had macular degeneration.
"Green eyes probably represent the interaction of multiple variants within the OCA2 and in other genes, including perhaps the red-hair gene," Duffy says.:') Hair color is in that boat -- that is, true red hair has a different color, while everyone else (other than albinos I suppose) has varied levels of a single pigmentation. Maybe that's why the guy suggests that.