I used to wear "smokey" eyeliner, both above and below my eyes but not extending out sideways much, and I never noticed anything odd about my two eyes.
For the last couple of years I've come to like the look of sharper "flicky" eyeliner above my eyes only. But when I put it on, 9 times out of 10, it comes out looking different on my two eyes. The angle of the "flick" is different or it goes out further on one side than the other, so I often ending up wiping off and redoing the outer part of one line. I've tried consciously lining everything up perfectly as I put it on, actually saying to myself "OK, this is extending about x mm beyond the corner of my eye and the angle is about y degrees", so in theory they should be exactly the same. They're not, so I think it must be my eyelids themselves that are a slightly different shape. It's not a massive difference and it's quite possible that nobody else would notice, but it slightly irritates me that I can't seem to get it quite right first time.
Has anyone else experienced this, and did you ever discover a trick to help you get it right, or did you just learn to embrace it in the end?