Knowledge of the quaternary structure of α-crystallin is required to understand the age-dependent superaggregation processes, eventually leading to lens opacification. Different approaches, e.g. sulfhydryl modification, chemical cross-linking, limited proteolysis and dissociation studies revealed new information, providing a basis for further studies of aging and higher-order structures. A model for the architecture of native α-crystallin from calf lens cortex, featuring subunit arrangement and surface exposure, will be presented.