I have a lot of sympathy and empathy here. My ds9 was born with visual deficits and seen 6 eye doctors (three optometrists and three ophthalmologists) between two different states since he was 13 months old. They've agreed that my son had (or would likely have) visual deficits, but they've differed on the course of action and treatment. None of them mentioned a possible diagnosis of cortical visual blindness or other factors though my son's vision from his left eye was very restricted (including tracking and convergence issues).
Ds9 was in vision therapy between 4-6 yrs old. It made a HUGE difference. Of course, last Mar, eye doctor #6 (a pediatric ophthalmologist) at one of the top (or the) children's hospital in the US told me that perhaps it was due to maturity and not vision therapy. I nearly cried and wanted to scream at him. It would be impossible for my son's vision to have improved the extent it did WITHOUT any vision therapy.
Anyone could possibly benefit from vision therapy, but some kids really need it. Their visual system doesn't integrate properly and needs some help. Most of our visual skills are learned and this means how the visual system gels with early motor skills and other developments is key. Visual acuity (20/20) is a small fraction of our visual skills, but it's the one most people are familiar with.
