An ophthalmological device comprising: a memory that stores a plurality of angiograms acquired by applying optical coherence tomography to a fundus of a subject's eye; a detecting processor configured to detect a feature point from each of the plurality of angiograms; an identifying processor configured to identify a plurality of feature point groups from among a plurality of feature points detected from the plurality of angiograms by the detecting processor , each of the plurality of feature point groups corresponding to a same site of the fundus; a transforming processor configured to transform at least part of the plurality of angiograms based on the plurality of feature point groups identified by the identifying processor ; a composing processor configured to compose two or more angiograms of the plurality of angiograms at least part of which has been transformed by the transforming processor , based on the plurality of feature point groups; an edge detecting processor configured to construct a plurality of edge images by applying an edge detection to each of the plurality of angiograms in the event that a process performed by any of the detecting processor , the identifying processor , the transforming processor , and the composing processor has failed; a distance image constructing processor configured to construct a plurality of distance images by applying a Hausdorff transformation to the plurality of edge images; and a second composing processor configured to compose the two or more angiograms of the plurality of angiograms by applying registration to the plurality of distance images. a memory that stores a plurality of angiograms acquired by applying optical coherence tomography to a fundus of a subject's eye; a detecting processor configured to detect a feature point from each of the plurality of angiograms; an identifying processor configured to identify a plurality of feature point groups from among a plurality of feature points detected from the plurality of angiograms by the detecting processor , each of the plurality of feature point groups corresponding to a same site of the fundus; a transforming processor configured to transform at least part of the plurality of angiograms based on the plurality of feature point groups identified by the identifying processor ; a composing processor configured to compose two or more angiograms of the plurality of angiograms at least part of which has been transformed by the transforming processor , based on the plurality of feature point groups; an edge detecting processor configured to construct a plurality of edge images by applying an edge detection to each of the plurality of angiograms in the event that a process performed by any of the detecting processor , the identifying processor , the transforming processor , and the composing processor has failed; a distance image constructing processor configured to construct a plurality of distance images by applying a Hausdorff transformation to the plurality of edge images; and a second composing processor configured to compose the two or more angiograms of the plurality of angiograms by applying registration to the plurality of distance images. <EOS>