A primary requirement for the award of the PhD degree is the successful completion of a thesis, the defense of the thesis as well as the comprehensive examination. An Advisory Committee is appointed for each student. The advisory committee is available to the student for help and guidance and reviews a student's progress to help ensure successful completion of the degree. By the end of their fourth term of enrollment (sixth term for part-time students) in the Vision Science program students must make a formal presentation of their proposed thesis research to their advisory committee. The minimum number of terms during which a student must register full-time is 4 (from an MSc degree). The maximum time for a full-time PhD is 12 terms (4 years). Students who require additional time must complete a Petition of Extension form and supply a timeline for completion. The School of Optometry and Vision Science, University of Waterloo, provides the only English optometric training in Canada leading to an accredited Doctor of Optometry degree. The school also provides a graduate program in Vision Science and Optometry. Extensive clinic programs support practical experience for students and health services for the public. <br><br>The advancement of understanding of the normal and abnormal development, structure and function of the ocular and visual sensory and effector/motor nervous components and the impact of neural senescence.