I am here because this question continues to pester me while living in Asia. Asians do not see well with peripheral vision. It is a blind spot for them - even if it is slight. But I cannot conclude if this is a matter of unable to see peripherally or a matter of how they use eyesight.
I use the peripheral sense a lot, and what I can't fully detect I turn my head. This is not so for my Asian counterparts here. I am constantly dodging people walking out of doorways on the street who nearly run into me (and often do) as they are turning to the left or right without sensing I am in that space. I see it in the way they walk and drive.
I can determine that they are using a slightly smaller field of vision (using less peripheral) but as to why I can only guess. It may be due to physical structures regarding the optical organ (eye folds, or cheek structures, etc.) or it may be due to how they are trained or conditioned to "see", in other words, it may be a cultural aspect to "see" or focus directly ahead with little regard to visual information further away from direct center.
In either case, I cannot say as to why, I can only say that based on observation and experience of many years in Asian countries (Korea, China, Japan, Thailand), this is a real phenomenon. I love the Asian people here, my observation is not about racial stereotyping. Some things tend to be true for a group of people and there are rational reasons behind it.