Adaptive optics scanning light ophthalmoscopy.

Scanning light imaging systems are broadly useful in many applications, especially when applied to ophthalmoscopy and vision science. This chapter aims to explain how and why they are useful. It starts by covering the basic principles of scanning systems and their history. Then it covers the ways in which scanning imaging systems are used in ophthalmoscopy, why they are so effective for ophthalmoscopy, and how the addition of adaptive optics has driven a paradigm shift in how scanning light ophthalmoscopes are used to study vision in health and disease. An adaptive optics scanning light ophthalmoscope is readily adaptable for many imaging modalities, including fluorescence, phase contrast, and even as a basic platform for optical coherence tomographic imaging. Applications beyond imaging include fast and accurate measurement of eye movements and the ability to administer functional tests, like acuity, sensitivity, and fixation. It is a technology that will continue to evolve and find use in ophthalmology and vision science.