In Vietnam, rental bikes come with bowler-style helmets. No protective visor. The locals basically all ride like that. I watched them and did the same. On the road, a tiny gnat flew straight into my eye. It got in so well that I couldn't get rid of it on my own. I couldn't even see it myself. But it was definitely uncomfortable.
I went to the nearest private clinic, and without any prior appointments, they took me straight to the doctor who pulled this thing out with a regular cotton swab. Man, it felt amazing to realize there was nothing in my eye anymore. For a few days after that, I got tired from screens much faster than usual, but eventually everything went back to normal. Riding bikes without eye protection is definitely not worth it.
Traffic in Ho Chi Minh City is absolutely insane. In smaller cities it's easier. The main rule is to give way to bigger vehicles. Nobody lets pedestrians through at all. You just have to throw yourself into traffic and hope they drive around you.
PS. If you're responsible and don't go anywhere without travel medical insurance, stay responsible all the way and thoroughly figure out how to use this thing BEFORE your trip. Dealing with it in an emergency situation is pretty rough. I checked. My instructions said "contact us on Viber and we'll tell you where to go." Except these Serbian guys showed signs of life 6 (six!) hours after I reached out, when I'd already given up and went to get help without their blessing. But they promised to reimburse everything.
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