PROJECT SUMMARY Age-related macular degeneration (AMD) is an eye disease that affects the central part of the retina and leads to impairments in central vision and sharp vision. According to the report from Centers for Disease Control and Prevention, AMD affects ~0.8% of people in US between 50 and 60, 1.5% between 60 and 70, ~4.8% between 70 and 80, and nearly 12% over 80 years old. Fluorescence lifetime imaging ophthalmoscopy (FLIO) has become an important tool in retinal diagnosis as it provides critical information about retina that the traditional fundus autofluorescence microscopy cannot provide. Whereas more demonstrations of FLIO in retina diagnosis at different stages of AMD have been shown in recent years, FLIO has not reached widespread use in clinics due to a number of fundamental limitations. Here we are developing an ultrafast fluorescence lifetime imaging ophthalmoscopy (uFLIO) system for rapid acquisition of retinal fundus autofluorescence and reconstruction of fluorescence lifetime images around the posterior pole of retina. The acquired autofluorescence lifetime information will help us understand the states of the endogenous fluorophores within the retina, and their roles and changes during the development of retinal diseases.