Purpose: This study examines the change in distance from the corneal limbus to the insertion of the rectus muscles before and after disinsertion and retraction with a pair of fixation forceps during strabismus surgery. Methods: In 38 strabismus patients, on 30 medial rectus muscles and 38 lateral rectus muscles, before and after disinsertion and retraction with a pair of fixation forceps, the distances from the corneal limbus to the upper, middle and lower parts of the insertion of the medial and lateral rectus muscles marked with methylene blue solution were measured. Results: The distances between the corneal limbus and upper, middle and lower parts of the insertion after the disinsertion were reduced on, average 0.23 mm, 0.28 mm, and 0.18 mm, for the medial rectus muscle, respectively, and 0.21 mm, 0.28 mm, and 0.15 mm, for the lateral rectus muscle, respectively (P