Alzheimer's disease (AD) is a neurodegenerative disorder with insidious onset and poor prognosis, and it is the primary cause of senile dementia. Its early diagnosis is challenging, and existing methods mostly rely on high-cost and invasive examinations. As an integral part of the central nervous system, the retina provides a non-invasive and efficient observation window for AD diagnosis. In recent years, with the development of ophthalmic imaging technologies such as optical coherence tomography, optical coherence tomography angiography, and hyperspectral imaging, a growing number of studies have revealed that AD patients exhibit retinal structural changes, structural and functional abnormalities of retinal blood vessels, and that amyloid-beta and Tau deposits can be detected via specific imaging methods—suggesting that these changes may occur prior to brain lesions. Meanwhile, the integrated analysis of multimodal imaging shows promising prospects in identifying retinal biomarkers and predicting AD risk, demonstrates the significant potential of retinal imaging technology in the early screening, diagnosis, and disease progression monitoring of AD, and provides a new source of biomarkers and potential clinical applications for AD research.