They could also easily differentiate between brown eyed and blue eyed people. The social construct part comes in when you try to explain why one differentiation is more 'important' than the other.

"eye color is a social construct" and "the importance of eye color is a social construct" are two completely separate ideas. OP clearly states '"race" is a social construct'.

> "eye color is a social construct" and "the importance of eye color is a social construct" are two completely separate ideas.

And that's the point. In ths case, "race" is equivalent to "the importance of eye colour", because "race" is the importance and social meaning we build around certain genetic differences.

If race is equivalent to the 'importance of eye color', does that mean 'the importance of race' is the 'importance of the importance of race'?

Why does race automatically have some kind of value judgement associated with it but eye color does not? Just because people have used it as a standard of other-ness in the past doesn't mean that the qualities have ceased to independently exist.

Eye color is a social construct because color is a social construct.

The presence of the genes for coloration is the only unambiguous thing, and even then it's vulnerable to all sorts of anomalies in gene expression (heterochromia, chimericism etc)

Color is not a social construct.

Yes, it is.

https://www.youtube.com/watch?v=gMqZR3pqMjg

I thought you might be going there with that. That is how our learning teaches us to classify colors into finite groups(/names). That does not mean that color itself is a social construct.

Right. Not having specific names for two colors is an entirely different thing from being unable to recognize that one color is different to the other.

They certainly could. But they wouldn't group Khoisans and Bantus together as "Black" compared to the Irish person being "White". Traditional racial categories fail to carve reality at the joints and modern geneticists will always use terms like "ancestry" rather than "race" because the later just has too much baggage to deal with.