I've been thinking a lot about eyes, and the reason why the eyes look fierce is because the tail of the eye is raised or the front of the upper eyelid is lowered.
If you look at Han Ye-seul, in the past, the front of the upper eyelid was lowered like the left picture, but now, as in the right picture, the front of the upper eyelid is lifted like a blue line, giving her gentle and cool eyes. What kind of surgery would be needed to raise the front of the upper eyelid like this?
I thought about it, and I wondered if it would be possible to raise the front muscle of the upper eyelid a bit more when correcting the eye shape, or to cut the sagging flesh on that side when cutting? What about forehead lifting? I think that surgery also makes the eyes look gentle.
If your eyes look fierce, try lifting the flesh between your eyebrows. You'll look much gentler and prettier. I think that's similar to the principle I wrote above.