asked the same question to my GP an few months ago
and he basically told me that in singapore ophthalmologist don't see children much... that I just had to take her to an eye glass store for the exam there...
in the end it's what I've done... she had more and more headaches... something needed to be done quickly... brought my daughter to an eye glass store... she is happy holder of a pair of glasses
except if the correction they need is a tricky one... some problems being harder to correct than others or if there is a problem with assessing really the eyesight ( some children can trick the computer... I could as a child... the doctor thought I had prefect eyesight, until he dilated my eyes... and then it was a whole other story... dilatation being the one thing that separates eye glass store of eye doctor for simple problems... )
then an eye glass store is enough...