This monocentric prospective longitudinal observational study will validate fundus-tracked dark adaptometry as an endpoint for future treatment trials in early and intermediate age-related macular degeneration (AMD). The study will characterize normative cone- and rod-mediated dark adaptation parameters in healthy volunteers, assess test-retest reliability, quantify sensitivity to change over time, evaluate diagnostic and prognostic validity against AMD stage and structural progression, and investigate imaging-, biomarker-, and genetics-based determinants of impaired dark adaptation.
Inclusion Criteria: * Written informed consent. * All biological sexes and gender identities. * Age \>=18 years for healthy volunteers; age \>=55 years for participants with AMD. * Ability to understand German or English sufficiently for study information and procedures. Additional Inclusion Criteria by Cohort: Healthy Volunteers: \- No drusen \>63 um and no subretinal drusenoid deposits in either eye. Early AMD: \- Study eye with drusen \>63 um but \<125 um and no pigmentary changes. Intermediate AMD: \- Study eye with drusen \>125 um and/or pigmentary changes. Exclusion Criteria: * Claustrophobia relevant to dark-adaptation procedures. * Hypersensitivity to indocyanine green or sodium iodide, iodine allergy, or hyperthyroidism. * Known pregnancy. * Study eye history of ocular surgery other than cataract surgery, YAG capsulotomy, or laser retinopexy. * Ocular disease in the study eye that could affect visual function testing in the opinion of the investigators. * Medical conditions or planned operations that could interfere with follow-up. * Inability to comply with study procedures or insufficient language skills in the study language. * Inability to provide informed consent.