A common stereotype about Asians is that they are "squinty-eyed." While this is, of course, based on the fact that Asians have a genetic propensity for an epicanthic (eye-lid) fold, adapted perhaps as a kind of shade against snow blindness, I think something contributes to the stereotype. And I will not say the perception of Asians as quiet and crafty gives them an imagined "sneaky appearance" (e.g., eyes slitted in collusive impenetrability). It's the reverse. Partly the epicanthic fold, but also something else, contributes to the stereotype of Asians as cunning and inscrutable. The other factor? They have bad eyesight.
I've lived in Taiwan over four years and have had lots of experience looking closely at Asian faces. (That's not a boast, just a statement.) I've been in close contact with Japanese, Indonesians, Filipinos, Koreans, et al. Further, I'm a teacher so I must constantly analyze students' faces for hints of understanding, curiosity, impertinence, shame, etc. And what I can say is that just as the myth of the docile, taciturn Asian was exploded countless times by the stunning raucousness of groups of happy students and adults, so the myth of the slanty-eyed Asian saw its demise the longer I saw those eyes. A great many Asians simply do not have a pronounced slant to their eyes... unless, that is, they are squinting.
And that's just the problem: they squint a lot here.
I can't tell you how many times I've been unnerved while teaching, seeing an otherwise sweet, upbeat student scowling at me while I talk. ("What did I say?") Or how many times I've felt my dander rising as people, total strangers, glower at me with thin eyes as I walk on the street, like some interloper. ("What did I do?") Or how clerks will peer at me inquisitorially and my seemingly contraband items. ("Did my make the most wanted list?") It took me a long time to realize all this scowling and peering is actually just a result of people's habit of trying to see more clearly. It's a documented fact that Asians, as a group, have more vision problems than, say, Caucasians, and that's largely because of their languages (being made up of intricate ideographs) and education systems (being hugely memory-based and text-intensive). Asians' eyes simply get more strained learning their own languages and going through school than other peoples' might. The same problem holds for serious non-Asian students of Chinese: their eyes deteriorate the harder they study. This is why the eyeglass industry is simply booming, in Taiwan, at least. You can find eyewear shops and optometrists about every few blocks. In my glasses, I mean, classes over the years, the vast majority of students all wear glasses... unless, that is, they forget to wear them. And this lapse is exactly what leads to all the squinting. Just as students will let their bike helmets fangle from the handelbars without wearing them, and adult scooter drivers will wear helmets without clasping the chin strap, so many people hear are perfectly fine going about the day with subpar vision, whether from not wearing glasses or wearing improperly prescribed lenses. (Indeed, in my last class I just saw a girl squinting with her glasses on!)
As my diction reveals, I'm speaking generally and tentatively about this. I can't claim any rigorous sociological proof for this factor in the formulation of a stereotype. In my defense, though, talking about stereotypes, generalities by definition, entails talking stereotypically, generally. My insight might seem as compelling as saying the that stereotype, "Americans are fat", arises from the fact that Americans wear baggy clothes. But, then again, that kind of logic can't be ignored when looking at culture. Asians seem like "squinty folk" because, the fact happens to be, they squint noticeably often! Such behavior is all the more striking in conjunction with having an epicanthic fold.