8yr old struggling with reading, time for ophthalmologist?

My 8yr old is struggling with reading and though he is in the 3rd grade, he is still at a 2nd grade level. He went to the optometrist a year ago and was prescribed reading gles for hyperopia. We were also told "his eyes don't track well together." He was given the following activities: saccades, pursuits & harmon dist. though only initially. When we read with him, he is guessing at words, not always with the same beginning letter and he needs a bookmark to follow the line. Should I follow the pediatrician's suggestion and take him to a pediatric ophthalmologist?