Open to National Orthoptic Associations meeting the following requirements:
- a national association which has been in existence for at least three (3) years and promotes the scientific and practical development of its members
- the existence of a national training programme with an acceptable syllabus
- nationally recognised qualifications
- satisfactory completion of the IOA application procedure
Full membership gives the National Orthoptic Association the privilege of a seat on the Council of Management and full voting rights.