I'm already aware of the knee and the eye, the knee'll be adjusted when I get back to that painting (pretty soon actually).
The eye however will stay as is. They were originally at the same height, but I fixed the height on the side I was rendering (right) and got lazy when it came time to render the left eye. Although if I have some spare time I may end up finishing that render.
I would, however, like some critique on the second piece the most. I can't bring myself to touch it. I'm at a loss for what I want to do with the background. =/
Personally I would work on the knees for the second drawing. Right now they look rather straight as they lead straight into the lower leg. However, since you are going for more realism, then I would suggest reciprocating the Z of the bones in the leg (particularly the weight bearing leg), and then making sure to build the knee muscles around it. I'm pretty sure you will understand what I mean... hopefully, but just incase - here you can see clearly how the muscles and such join into the knee to give that rounded look to it: