The present disclosure relates to an optical coherence tomography (OCT) including: an OCT device, an OCT calculation method, and an OCT calculation program, enabling correlation between images to be easily performed more specifically it relates to a case where a functional OCT image such as a motion contrast is acquired by using the OCT acquiring the functional OCT image through a calculation process of an OCT signal is a time-consuming process, for this reason, a long time elapses until the point that a functional OCT image can be observed after OCT imaging is completed, and thus this causes stress to a subject and an examiner the present disclosure provides an OCT device, an OCT calculation method, and an OCT calculation program, enabling a functional OCT image to be rapidly acquired and enables an examiner to easily perform diagnosis.
