It's called kohl, and it's been around as eye protection from the sunrays and bacterial infections for a long time. Nowadays it's kind of a cultural holdover more than anything for both men and women in Middle Eastern and North African countries.
Like if you look at Ancient Egyptian or Mesopotamian art, they are depicted with it around their eyes (like eyeshadow + concealer today). Greeks probably wore it more like eyeliner, if we go by amphora depictions.
Modern day you have people wearing it just as a thin line around both eyelash lines, or on the waterline (the inside part of your eyelash line that touches your eyeball). Some people just do the outer corner of the eye, some draw dots on the eyelid. A lot of these techniques may have had cultural/tribal importance too that have been lost to time, but the aesthetic remains.
I don't know how people do it the waterline though, my eyes tear up just thinking about it.
You've helped detail what I thought was just a trend in makeup, thank you. I haven't ever put makeup on myself, outside of a few plays when I was a kid/teenager, so I'm right there with you.
Do you happen to know what it's typically made of? I'm reading it's traditionally made by grinding up stibnite into a powder, but I'm also wondering if that's true because stibnite is supposed to be toxic. I would imagine it would be bad to put on your eyes like that, no?
Stibnite is the traditional ingredient, but I'm not sure if that's used nowadays (at least I hope not!) I know in rural communities homemade kohl can have a charcoal base. But I think most are just using store bought stuff which (hopefully) adhere to product safety standards!