Good question, I don't know the answer.
However, it can be quite a Eurocentric or North American/caucasian-centric proposition.
I remember fluffing an internal job interview for a role in an organisation where I was already working, and I didn't get the permanent job, even though I was covering the role as a 'temp'. Anyway, a colleague gave me a book about interview skills, to help me overcome my difficulties, and I remember reading something about eye contact and cultural differences. It was talking from the perspective of the interviewer, and it mentioned something about taking into account cultural differences, along the lines that from a European/caucasian perspective, direct eye contact is a sign of someone being straightforward and honest, whereas looking away can be interpreted as being shifty or dishonest, so a European/caucasian candidate might look an interviewer in the eye as they answer questions...
Whereas from an Afro-Caribbean perspective, direct eye contact can be perceived to be aggressive, so people of that ethnic background would tend not to look an interviewer in the eye as they answered questions, and of course if their interviewer was European/Caucasian, this body language/non-verbal communication might be negatively perceived. (It was a long time ago, and it was a book for the UK job market).
I've just Googled cultural differences eye contact and come up with a reference stating that in Asian cultures, direct eye contact can be disrespectful.
So who knows what it's all about, and how cultural differences might come into play...
perhaps people from Afro-Caribbean backgrounds might be under-diagnosed or misdiagnosed, if cultural differences dictate that they tend not to engage in direct eye contact?
Anyway, as for the other visual stuff, I have mild prosopagnosia but otherwise very good eyesight. There doesn't seem to be a predominant visual quirk that's common to a majority of Aspies, although it's not unusual for Aspies to be affected in some way by one of them.