Squint, Cross-eyed

If you have any interest in the doctor-patient relationship, I very much recommend Dariusz Galasiński's blog. He writes thought-provokingly about various things that he and I have in common: being immigrant linguist patients or linguist immigrant patients or immigrant patient linguists. But probably not patient linguistic immigrants. Anyhow, we're rather different in how we are/do all those things, but I am really enjoying the commonalities and the thought-provocations.
He wrote recently about a term that's always struck me when I've heard it in BrE. Here's a snippet from the relevant blog post, On 'medical language': ...I was asked about ‘the history’ and told about my strabismus. The optometrist (or doctor) responded with something like:
OK, so you had a squint.I didn’t react the first time, but after a second time, I politely but firmly said I hadn’t – it was strabismus, to which she said, it was one and the same thing. And I somewhat more firmly said it wasn’t and that I would rather she used medical language. She looked at me with a sort of ‘What’s your problem, man?’ look. I so didn’t care.
You see, there is nothing ‘squinty’ about my strabismus. It’s not a squint, it’s not ‘strab’. No, it’s strabismus. For me (and I only speak for myself) when you use colloquial language to refer to my eyes, you make light of all the sh…I had to take when I was a boy....In AmE, it's said that a person with strabismus is cross-eyed or more rarely that they have a crossed eye. I was told when I was young that cross-eyed means the eye (or eyes) points toward(s) the nose and wall-eyed means it/they point away from the nose. That wasn't the original meaning of wall-eye (no, that was having a very light iris). I imagine that the strabismus meaning came from folk-etymology: the eye is looking at the wall. (Also, there's a fish called a wall-eye and fish generally do look to the side.) But in everyday US usage, cross-eyed seemed to be applied indiscriminately for any off-target eye.
In young children, who were treated with an eye patch, the term lazy eye was used, and though there seems to be a technical difference between that and strabismus, I don't think anyone in my circle was observing the difference. This term seems to be used in both countries.
But I had never heard of squint to refer to strabismus till I came to the UK.
In AmE squint generally means narrowing your eyelids, as you do when the sun's in your eye. This meaning is only a bit more than a century old (three hundred years younger than the strabismus sense). Despite its newness, it's a widespread meaning, which has definitely arrived in the UK. This is what you get if you google "Squint emoji":

The scrunched-eyelid meaning is mostly used as a verb (she squinted in the sun), whereas the  strabismus meaning is mostly used as a noun, following the verb to have: he had a squint.
While US dictionaries have the older meaning (though maybe not listed first), squint does not seem to be used much in the US in this way. There are nine British examples of ha* a squint in the GloWBE corpus, and though it initially looks like there are three "American" examples, one is the narrow-eyed meaning and the other two aren't by Americans.Why did the strabismus meaning die out in the US? Probably because of the success of the narrowing-your-eyes meaning, connected to the fact that cross-eyed had come along (late 18th c) to do the strabismus job.
Back to Dariusz's post, the tendency of UK medical folk to use colloquialisms--some of which I might classify as 'baby talk' or 'euphemism' is something that's come up here before. (Here's a link to the medicine/disease tag, where related things come up.) It depends on the ailment, but by my tally, the UK does more colloquial terms, the US more medical jargon. Whether BrE medical personnel perceive squint as colloquialism or just "the normal (non-medical) word" for the condition, I don't know.
The point of Dariusz's post (as I read it) is not "people shouldn't use this word", but more "medical personnel shouldn't assume that colloquialisms are the best way to talk to all patients" and "using colloquialisms with some patients may make them feel talked-down-to"—particularly in this case where the patient had used one kind of word and the practitioner had "dumbed-down" the patient's language—that seems dismissive. This is an issue I've had trouble with in dealing with a few UK doctors (and different medical issues) myself--simplifications that are oversimplifications or insistent use of euphemism where I'm using medical terminology.
But I don't want to end on a sour note about UK doctors. (I love the NHS!) American doctors have their own communication problems with patients. A major theme of Dariusz's blog is that doctor-patient/patient-doctor communication should be human-human communication. The problem with that wonderful idea, of course, is that some people on both sides of the pond are trying to make medicine profit-driven. Human relationships hardly stand a chance in those conditions. But let's not stop trying.
[Late addition] A Twitter correspondent offers boss-eyed. Oxford Dictionaries lists it as 'British informal', and the not-updated-since-1933 OED entry lists it as 'dialect slang' and referring to just one eye out of alignment. 

****By the way, I'm happy to report that I have submitted the manuscript for the book that this blog inspired. I will let you know publication details when they are available (you know I will)--but the book won't be out till some point Spring 2018. Yay! And thank you to the (US) National Endowment for the Humanities for making it possible.