PROBLEM TO BE SOLVED: To allow a fibrosed region of a polarization tomographic image of a subject eye to be so displayed as to be easily distinguished.SOLUTION: An image processing device includes: signal processing means for generating phase delay information of a subject eye by using plural light beams obtained by dividing, into light beams of polarizations different from each other, light obtained by multiplexing returned light from the subject eye irradiated with measurement light and reference light corresponding to the measurement light； and detection means for detecting a region in which variation of the phase delay information in a depth direction of the subject eye is larger than a threshold value.SELECTED DRAWING: Figure 6【課題】 被検眼の偏光断層画像の線維化領域が識別し易いように表示させること。【解決手段】 画像処理装置が、測定光を照射した被検眼からの戻り光と測定光に対応する参照光とを合波して得た光を互いに異なる偏光の光に分割して得た複数の光に基づいて、被検眼の位相遅延情報を生成する信号処理手段と、被検眼の深度方向における位相遅延情報の変化量が閾値よりも大きい領域を検出する検出手段と、を有する。【選択図】 図６
