This section does not apply to a child whose physical condition makes the child’s instruction under this section inexpedient or impracticable. Each blind child shall attend a school or classes for the blind during the school year unless the child otherwise is receiving regular, thorough instruction during the school year in studies usually taught in the public schools to children of the same age. A superintendent or principal of a school for the blind or an individual authorized by a superintendent or principal may excuse a blind child for a necessary absence. Each person who has a blind child under the person’s control shall see that the child attends school or receives instruction as required by this section.