photofraction test on toddler. advice..?

[haven]

has anyone had this kind of eye test done in a peds. office? how accurate is the test? how far away did they have to be? what about light?

my ds had this test a while back and the nurse said he barely past, but the ped said his eyes were o.k...(don't worry) ....but, one eye tends to pull...should i bring him to an eye specialist...or take the peds advice or the nurse that said he barely past....?