Growing evidence suggests that Alzheimer's disease (AD) pathology is not confined to the brain but also appears in the neurosensory retinaRetina. The retinaRetina, viewed as an extension of the brain, is a neural tissue easily accessible for direct and noninvasive imagingImaging at the vascular, cellular, and molecular resolution. Postmortem examinations of AD patients’ retinasRetina, including those in early stages, have identified Aβ accumulations, vascular Aβ40 and Aβ42 deposits, hyperphosphorylated tau inclusions, microgliosis, astrogliosis, MMultiple Sclerosis (MS)üller glia changes, abnormal electroretinography patterns, and neuronal degeneration. Several studies further provided data suggesting that the brain and retinaRetina follows a similar trajectory during AD progression, possibly due to their common embryonic origin and anatomical proximity. In vivo fundusFundus imagingImaging, optical coherence tomography (OCTOptical Coherence Tomography (OCT)), and OCTOptical Coherence Tomography (OCT)-angiopathy have detected various retinal vascular abnormalities in preclinical AD, mild cognitively impaired (MCI), and AD dementia patients, including reduced blood flow, blood vessel tortuosity, and increased foveal avascular zone and arteriole-to-venule ratio. Moreover, histological analyses of postmortem retinasRetina of MCI and AD patients revealed early and progressive vascular platelet-derived growth factor receptor-β (PDGFRβ) and pericyte losses along with endothelial tight-junction deficiencies. Retinal vascular damage was closely associated with increased retinal vascular amyloidosisAmyloidosis, cerebral amyloid angiopathy, and cognitive deficits. Proteomics profiling has revealed common molecular signatures in the AD retinaRetina and brain, with enriched pathways related to inflammatory, vascular, mitochondrial, and photoreceptor vulnerability. Notably, novel imagingImaging techniques, such as curcumin fluorescence of retinal Aβ deposits detected by scanning laser ophthalmoscope and hyperspectral imagingImaging indicated increased retinal amyloid burden in AD, which was correlated with hippocampal atrophy and brain amyloid-PET load, and together with vascular changes, was predictive of cognitive decline. This book chapter provides an overview of the evidence of AD pathology in the retinaRetina, AD-related visual dysfunctions, and ophthalmic imagingImaging modalities, while also highlighting the current gaps in knowledge that should be addressed in future studies. With recent advances in anti-Aβ immunotherapies for early AD cases, noninvasive retinal imagingImaging strategies may fundamentally transform the feasibility for early screening and monitoring of AD.