It may be that the blurring out of more distant objects is developmentally useful as it helps babies to concentrate on those vital faces undistracted by other things.
What does "out" mean here? It even seems to me that "out" is not necessary in the sentence...
I agree: it's an odd way to put it, but, nevertheless, it's useful.
Originally Posted by Taka
It means, to blur X out (of one's sight), to remove X from one's sight altogether.
All the best, :D
So does "out" here mean "completely" or something?
I would imagine so- I'd interpret it as 'blurring until they were no longer visible'.