CorvusCorax
'It's only a laugh, no harm done'
Humans are wired to try and read other animals/people via their eyes to decide whether they are in potential danger (the term ‘murderers eyes’, for instance). If you pair very strange eyes with a huge, muscular dog that has a jaw larger than a small human head, it’s no wonder it gives people the heebie jeebies and that their behaviour and body language will alter around that dog.
I imagine if he were a short coated dog without the ‘redeeming features’ that humans like, peoples behaviour would likely change towards him.
Interestingly, he really sets other dogs off, even when he's paying them no attention at all, to do with his colour, tail carriage, ear-set, etc.
As you mention, I have a friend of eastern European extraction with piercing blue eyes and we always joke that he has 'the eyes of a killer'.