The human eye is an imperfect refractive system which has kinds of aberrations, including on-axis aberrations and off-axis aberrations, all of which have influence on the imaging quality of retina. But at present most of the ocular aberration detection methods focus on on-axis measurement, such as defocus, astigmatism, and part of high orders aberrations. The ocular off-axis aberrations detection method based on the Hartmann-Shack is proposed, the measuring system is set up and the experimental test is carried out. When the off-axis angle changes from 0
around to 5
, 10
, root mean square(RMS) values change from 1.12 to 1.36 (1.52), and 1.41 (1.96), and the results show that with the increase of the off-axis angle, the image quality of human peripheral vision decreased significantly. The reason is the increase of the off-axis aberrations, the other reason is due to the decrease of the peripheral vision photoreceptor cells density.