Purpose.To report three cases of seemingly unilateral dystrophy indistinguishable from type I classic lattice corneal dystrophy.Methods.Case study of three patients. Three patients, a 31-year-old man, a 44-year-old woman, and a 41-year-old man had multiple lattice lesions in one eye and an apparently healthy fellow eye. Two of these patients underwent penetrating keratoplasty because of poor vision.Results.Histopathologic examination of the excised corneal button of patient 2 showed amyloid deposits consistent with lattice. In the third patient, lattice lesions were noted in the other eye nearly 13 years after he was first examined.Conclusions.Lattice corneal dystrophy is rarely unilateral. Lattice, even in unilateral cases, may cause significant vision loss to warrant penetrating keratoplasty. Lattice lesions may develop in the fellow eye many years later. This possibility should be explained to all patients with apparently unilateral lattice corneal dystrophy.