Source: http://www.aoa.org/x5106.xml
As a non-practicing optometrist who is a full-time student in an accredited institution of higher education, you are eligible for direct membership in the AOA as a postgraduate member. Postgraduate membership is complimentary and continues until the end of the calendar year in which you complete your residency. Certification of your full-time status as a student must be made by an appropriate official of the institution and must be noted on the application. The postgraduate classification must be renewed annually.