Despite differences in frequency, causation, and infectivity, adenovirus epithelial keratitis and Thygeson’s superficial punctate keratitis (TSPK) are often confused in clinical practice owing to the similarity between adenovirus epithelial infiltrates and ‘coarse’ epithelial TSPK lesions. This book presents the morphological features, dynamics, and sequelae of adenovirus and Thygeson’s keratitides captured at high magnification in the living human cornea. It thereby fills the existing void between conventional photographs and slit-lamp observations. Case reports demonstrate the importance of patient history in differential diagnosis, illustrate the need for familiarity with early manifestations of adenovirus infections, and assist in the diagnosis of rare variants of TSPK. Furthermore, the detailed observations on the natural course of the diseases ensure that the book will serve not only as a diagnostic tool but also as a reference when evaluating the effects of potential new treatments.