The small size of the eye has precluded many efforts to image ophthalmologic disease processes. An understanding of those areas where nuclear medicine has been successful in ophthalmology requires a review of the appropriate anatomy. The accessibility of the nasolacrimal system and its pumping action have allowed for a unique physiologic appraisal with nuclear medicine techniques. The "magic bullet" that has eluded the search of oncology has left ophthalmologists without a practical diagnostic modality for ocular cancers. However, by placing detection devices in close proximity to these tumors, some useful information can be obtained. Unfortunately, this requires surgical dissection. New techniques have already been introduced into ophthalmology (fluorophotometry) in diabetic disease of the eye and nuclear medicine may have a considerable impact in this area. Understanding the anatomy of the retinal capillaries and larger vessels is essential to the reading of the pioneering work of Freeman and coworkers.