Multiple myeloma (MM) is the second most common neoplastic blood disease worldwide. Belantamab mafodotin is a new antibody conjugate anti-B-cell maturation antigen effective against refractory myelomas. It induces intracorneal microcysts leading to refractive fluctuations. The aim of this study is to assess the value of monitoring refractive fluctuations based on the location of microcystic-like epithelial changes (MECs) to facilitate patient follow-up.