The Department of Education shall create the position of visiting teacher to blind children of preschool age. With the consent of the parents of any blind child of preschool age it shall be the duties of such visiting teacher to assist and instruct the parents in the early care and training of said child, to train the child in play, and to do everything which will assure the child’s physical, mental and social adjustment to its environment. The Department of Education shall maintain a sufficient number of visiting teachers to adequately serve the needs of parents of preschool blind children in accordance with the known number of such children. In any event the caseload of each visiting teacher shall not exceed a number of clients that can be adequately and fully served.