Adult-onset myopia is most often reported in college age individuals. Its prevalence and the refractive component(s) responsible are essentially unknown; some recent studies implicate corneal curvature. Here I present a single case of adult-onset myopia over a period of 23 years in which axial elongation, and not steepening corneal curvature, is suggested as the most likely basis for the 4.50 D increase in refractive error.