A non-invasive ocular light-based detection device for detecting Alzheimer's Disease (AD)- associated pathologies in the retina of the eye. The device uses two imaging modalities where one imaging modality guides the particular regions to be interrogated by the second imaging modality. A hyperspectral reflectance imaging unit detects light reflected and/or backscattered off of the retina from a broadband light source, which is used to determine one or more regions of interest. A Raman spectroscopy unit detects light that is re-emitted by the retina by Raman scattering phenomenon from a laser that is targeted onto a region of interest that is determined from hyperspectral reflectance information. The detected information from the hyperspectral reflectance imaging unit and the Raman spectroscopy unit are used to determine the presence of the one or more AD-associated pathologies. The detection device allows for the identification of at-risk populations, diagnosis, and tracking of patient response to treatments.