Retinal alterations may predict early prodromal signs of neurodegenerative diseases. This review discusses the relationship between retinal degeneration and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). The retina shares anatomical and functional similarities with the brain, and retinal changes may reflect underlying brain pathologies. In AD, amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) are hallmarks, and these may also appear in the retina. In PD, α-synuclein deposition in retinal cells and dopaminergic neurons of the substantia nigra alters retinal function and visual field. Retinal analysis could serve as a non-invasive method for early diagnosis of these diseases, offering a cost-effective alternative to functional and structural brain imaging. The retina's layered structure and its connection to the central nervous system make it a valuable window for detecting early signs of neurodegeneration. Retinal electrophysiological tests, such as electroretinogram (ERG) and visual evoked potential (VEP), can assess retinal and visual cortex function. In AD, retinal thickness and ganglion cell layer changes are associated with disease progression. In PD, retinal ganglion cell dysfunction and optic nerve damage are observed. Retinal biomarkers, such as Aβ and p-tau deposits, may indicate early disease stages. These findings suggest that retinal analysis could be a valuable tool for early detection and monitoring of neurodegenerative diseases.Retinal alterations may predict early prodromal signs of neurodegenerative diseases. This review discusses the relationship between retinal degeneration and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). The retina shares anatomical and functional similarities with the brain, and retinal changes may reflect underlying brain pathologies. In AD, amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) are hallmarks, and these may also appear in the retina. In PD, α-synuclein deposition in retinal cells and dopaminergic neurons of the substantia nigra alters retinal function and visual field. Retinal analysis could serve as a non-invasive method for early diagnosis of these diseases, offering a cost-effective alternative to functional and structural brain imaging. The retina's layered structure and its connection to the central nervous system make it a valuable window for detecting early signs of neurodegeneration. Retinal electrophysiological tests, such as electroretinogram (ERG) and visual evoked potential (VEP), can assess retinal and visual cortex function. In AD, retinal thickness and ganglion cell layer changes are associated with disease progression. In PD, retinal ganglion cell dysfunction and optic nerve damage are observed. Retinal biomarkers, such as Aβ and p-tau deposits, may indicate early disease stages. These findings suggest that retinal analysis could be a valuable tool for early detection and monitoring of neurodegenerative diseases.