Here's what helped me...I went to a 6 o'clock hold...I used to have my flintlock sighted in dead on and held to the center of the target, doesn't work for me any more...I'm 52, have terrible vision and had my retna detach about 6 years ago, which had to be repaired by laser surgery, so my right eye isn't as sharp as my left one...

Might try sighting in your guns higher and try the 6 o'clock hold...I don't have fiber optics, I have the traditional silver front sight...I also opened up the rear notch with a file, as it's a little fuzzy and was hiding the front blade...