I was diagnosed with amblyopia (lazy eye as I knew it) when I was very young.  My parents noticed that my right eye did not focus and kind of wandered around.  Also I was severely nearsighted.  I was actually legally blind in my right eye when I was diagnosed.  There are different levels of amblyopia and mine was pretty bad.  My mom said everytime I would walk out of the kitchen I would run into the regrigerator (it was on my right side) and likewise I would turn the corner from the hallway into the living room and hit the wall.  I had to see a specialist and eventually had to have surgery at age 6 to correct the problem.  I had glasses from a very young age and about age four to five they tried to make the muscles in my right eye gain control by putting an eye patch (like a big bandaid) over my good eye.  But it didn't work for me and so the last resort was surgery.  I am still nearsighted of course and also have astigmatism so I still wear glasses.  But the amblyopia is gone.  It can be hereditary and although I haven't had my kids to the eye doctor yet (shame on me they are getting older and I know the school exams aren't that good) I am taking my son soon because he has been doing little things that I know can be related to lazy eye.  Like at the dinner table he has been setting his milk cup down on the edge of his plate instead of next to it and it spills, but he says it looks to him like the cup is going to set next to the plate.  Of course this could also be happening because he is eight and doesn't pay attention to what he is doing, but my father had it too and my grandma said he did things like that all the time too.