HEMIFIELD SLIDE DIPLOPIA FROM ALTITUDINAL VISUAL-FIELD DEFECTS

We report two cases in which heteronymous, altitudinal visual field de fects resulted in loss of fusion and transient overlap of preserved he mifields. This phenomenon resulted in complaints of diplopia similar t o that described as ''hemifield'' slide previously described by tempor al hemianopsias. These cases illustrate that generalized loss of fusio n, and not the particular type of hemianopic field defect, is responsi ble for the symptoms known as hemifield slide.