I breed BEW/Dalmatian rats, and see this often. The piebald spotting gene can cause decreased pigmentation in the iris. I see it rather often in my piebald kiddos, as do other breeders breeding the piebald gene.
It's nothing 'special', and no, those are not "blue eyes". They are black eyes, which were mildly diluted by markings so are giving off a lighter tint with flash. In normal light, and genetically that rat is a Black Eyed rat.
The trait is also not something that seems to be "genetic". Breeding two parents who showed that trait, but were and genetically black eyed, has never given me a whole litter of those weird "piebald eyes" as I've been calling them as a nickname. Instead no matter the litter, it's always hit or miss whether I'll get those kiddos, or regular-eyed kiddos, and since you can't even see the trait past infancy, it's nothing special IMO.
I'm a firm believer that this is random pigment decreased by the piebald marking gene. It could hypothetically be related to odd eyes, who are also due to pigment displacement caused by markings.
Emily~