There's also a comparison, which I like EVEN better, that Lana is Green K (as above), therefore his weakness, and Lois is the Sun, therefore his strength.
Clark would stumble and fall near Lana because of the green-k pendant that she wore.
Lana made him WEAK. He felt weaker when she was around.
In Pandora he tells Lois that she makes him STRONGER:
Clark:
you can lean on me for strenght. I feel stronger when you're around, anyway.
Andreia