I haven’t read all the comments, but speaking as someone who lack depth perception and hence NEVER sees a distance - I definitely lean when I’m worried/nervous/not as confident (show nerves definitely encourage leaning). My main issue is that I get worried (probably from a lifetime of not knowing exactly where things are) that I’m going to miss the distance (my horse keeps telling me this is her job, quit trying to do her job) and I look at the jump. Looking down creates leaning forward, creates leg off. I practice at home as well, and do it over EVERYTHING - if I’m not paying attention, I will look down over trot poles so I am very concious about “eyes up”.
My solution - get straight to the jump then pick a spot beyond the jump and STARE at it. I end up back and with my leg on. I thought I was not looking down as much as I was until a lesson with someone and she noted that like a half stride from the jump, I look down - but I don’t always focus on the jump so I don’t “See” myself looking down but I don’t have a memory of where I was looking - as if my eyes were closed over the jump.
Eyes up keeps me back,leg on and I am much more with my horse jumping.
Funny story…I have taken to screaming “eyes up” at myself at shows (especially this year, as I moved up a level). I was out on cross country, screaming eyes up at myself over a jump and there were these poor competitors that were say 50ft beyond the jump and well out of the way. I felt bad that they may have thought I was yelling at them so I tried to clarify as I galloped past but that may have just made me seem like a crazy person…so if you are in Area II and see someone coming around on the cutest little bay mare you ever did see (it’s true, just ask her) screaming eyes up, don’t worry, it’s not you, it’s me.