My husband has amblyopia, as do several members of his family. at what point should we consider having our child screened?

As a baby: Your pediatrician should be looking at your child's eyes at all the regular check ups visits. Each time s/he will make sure the pupils are reacting properly, the eyes move as they should, and they are aligned correctly.

Ped can do: Your pediatrician can detect anything obvious. There is a modest hereditary aspect to misaligned eyes. Meanwhile you can do a quick check at home with your digital camera. Look at photos of the child - if the red eye is consistent in both eyes, then a problem is unlikely. If one eye is always dark consistently, it may have a risk for amblyopia - then you should be screened.