An information processing apparatus comprising: an acquisition section configured to acquire images of a real object captured by a predetermined imaging section, and position information of the imaging section based on at least one of a position and a direction of the imaging section, wherein the acquisition section is further configured to acquire images of a user's eyes captured by a second imaging section; a detection section configured to detect a line of sight of the user; an estimation section (103, 111) configured to estimate a start position and an end position in a real space, on the basis of a first image and a second image which are the images captured with the imaging section at each of a first viewpoint of the imaging section in the direction of the real object and a second viewpoint of the imaging section in the direction of the real object, wherein the first viewpoint corresponds to a first position of the imaging section and the second viewpoint corresponds to a second position of the imaging section, and configured to estimate a first position information of the imaging section at the first viewpoint and a second position information of the imaging section at the second viewpoint, wherein the estimation section (103, 111) is further configured to estimate the start position on the basis of the detection result of the line-of-sight at the first viewpoint, the first image, and the first position information, and to estimate the end position on the basis of the detection result of the line-of-sight at the second viewpoint, the second image, and the second position information; and a measurement section configured to measure a distance between the start position and the end position on the basis of the estimation result. an acquisition section configured to acquire images of a real object captured by a predetermined imaging section, and position information of the imaging section based on at least one of a position and a direction of the imaging section, wherein the acquisition section is further configured to acquire images of a user's eyes captured by a second imaging section; a detection section configured to detect a line of sight of the user; an estimation section (103, 111) configured to estimate a start position and an end position in a real space, on the basis of a first image and a second image which are the images captured with the imaging section at each of a first viewpoint of the imaging section in the direction of the real object and a second viewpoint of the imaging section in the direction of the real object, wherein the first viewpoint corresponds to a first position of the imaging section and the second viewpoint corresponds to a second position of the imaging section, and configured to estimate a first position information of the imaging section at the first viewpoint and a second position information of the imaging section at the second viewpoint, wherein the estimation section (103, 111) is further configured to estimate the start position on the basis of the detection result of the line-of-sight at the first viewpoint, the first image, and the first position information, and to estimate the end position on the basis of the detection result of the line-of-sight at the second viewpoint, the second image, and the second position information; and a measurement section configured to measure a distance between the start position and the end position on the basis of the estimation result.