[Part 3 of 5] This dataset comprises 500 high-resolution transmitted light microscopy images of Descemet’s membranes (DMs) collected from patients with Fuchs endothelial corneal dystrophy (FECD) at advanced stages requiring keratoplasty. The images were acquired as part of a multicenter study to establish a phenotypic classification system for FECD and investigate its correlation with CTG18.1 trinucleotide repeat expansions.