[thedoc (OP)]

Adam asked the Naked Scientists:
   What is the evolutionary advantage of different eye shapes
What do you think?

[alancalverd]

Assuming this refers to humans, it is likely that there was a migration of early homo sapiens towards the Far East via the northern latitudes. Arctic hunters use slit goggles to shield their eyes from snow glare. It is possible that people with "narrow eyes" (essentially, high cheek bones) fared better in that migration than those with "round eyes". But it's a pretty wild guess.