A camera in which focus is detected for a plurality of viewfields within a selected observation block includes observation structure for observing an object therethrough, and visual axis detecting structure for detecting the position of the visual axis of an observer's eye. A plurality of observation blocks are defined, each block having a plurality of detection viewfields. Structure is provided for selecting one of the blocks in accordance with a result of the detection of the visual axis detecting structure. Focus detection circuitry is provided for performing a focus detection operation with respect to the detection viewfields which are included within the selected observation block. Circuitry is also provided for forming a focus adjustment signal for an objective lens on the basis of the detection information of the focus detection circuitry regarding the detection viewfields of the selected observation block.