Hey I'm a heterochromic!! :-) In fact my eyes are completely different, my doctor is surprised I can focus at all. My pupils dilate differently too and of course my vision is different in each eye (that is common though).
I've only known one person who had a spot in the white of her eye, but it was due to trauma and surgery. If his eyes hurt, it could be the spotting, but it could also just be a focusing issue. I'm hoping its not serious. My prayers are with you.
And just like the other mothers said... please keep us posted. Remember, we are mothers and we all have a tendency to worry (even about other people's kids). :-)