Court consider the medical opinion given by one or more physicians designated by the Secretary in deciding medical equivalence. Disability finding for widow's benefits requires meeting or medical equivalence to a listed impairment. It is for the Secretary, not the court, to resolve conflicts in the evidence. The weight to which opinions of medical advisors are entitled will vary with the circumstances, including the nature of the illness and the information provided the expert. Obviously, the fact that the experts have neither examined nor testified lessens the probative power of their reports.