How do optometrists know if a baby needs glasses or not?

Question

I was in the dentist's office and i saw a baby with glasses. How do the optometrists know they need glasses if they can't take the eye test? (You know the one where you have to read the letters on the paper)

Answer 1

The main thing that the doc will look for with the baby is that both eyes move together. This indicates that the optic nerves are functioning properly. I imagine glasses would be a tough sell to a baby.