Dark-skinned and blue eyes

[Glordit]

Blue eyes is a mutation, anyway. So yeah, aliens.

Not entirely(speaking under correction here but I am positive this is true somewhat) blue is less absorbent to light than a darker colour. Also why people wear sunglasses in extremely cold climates, as snow reflects almost +70% sunlight/UV back again causing snow blindness.

***EDIT
Photokeratitis is the condition if the iris is exposed to too much UV light.