Method for determining at least one optical parameter of an eye of a person comprising: - displaying at least two sharp images on a retina of the eye of the person, the at least two images comprising a target and being carried by two light beams focused substantially in the plane of a pupil of the eye at at least two different positions; - adapting a parameter of the target in each image based on feedback of the person relative to the change of the parameter of the target in the image in order to superimpose the targets of the at least two sharp images; and - determining the at least one optical parameter of the person's eye based on the adaption of the parameter of the target in each image wherein the adapted parameter of the target is the relative position or the size of the target in each image, wherein adapting the relative position of the target in each image comprises: - adapting a horizontal angular position of the target of an image carried by one of the light beams until the target of the image and the target of another image carried by another of the light beams are seen by the person with the same horizontal position in the displayed images on the retina of the eye; - adapting a vertical angular position of the target of an image carried by one of the light beams until the target of the image and the target of another image carried by another of the light beams are seen by the person with the same vertical position in the displayed images on the retina of the eye and, wherein adapting the size of the target in each image comprises: - adapting a size of the target of an image carried by one of the light beams in a horizontal direction until the target of the image and the target of another image carried by another of the light beams are seen by the person touching each other in the horizontal direction in the displayed images on the retina of the eye; - adapting a size of the target of an image carried by one of the light beams in a vertical direction until the target of the image and the target of another image carried by another of the light beams are seen by the person touching each other in the vertical direction in the displayed images on the retina of the eye. - displaying at least two sharp images on a retina of the eye of the person, the at least two images comprising a target and being carried by two light beams focused substantially in the plane of a pupil of the eye at at least two different positions; - adapting a parameter of the target in each image based on feedback of the person relative to the change of the parameter of the target in the image in order to superimpose the targets of the at least two sharp images; and - determining the at least one optical parameter of the person's eye based on the adaption of the parameter of the target in each image wherein the adapted parameter of the target is the relative position or the size of the target in each image, wherein adapting the relative position of the target in each image comprises: - adapting a horizontal angular position of the target of an image carried by one of the light beams until the target of the image and the target of another image carried by another of the light beams are seen by the person with the same horizontal position in the displayed images on the retina of the eye; - adapting a vertical angular position of the target of an image carried by one of the light beams until the target of the image and the target of another image carried by another of the light beams are seen by the person with the same vertical position in the displayed images on the retina of the eye and, - adapting a horizontal angular position of the target of an image carried by one of the light beams until the target of the image and the target of another image carried by another of the light beams are seen by the person with the same horizontal position in the displayed images on the retina of the eye; - adapting a vertical angular position of the target of an image carried by one of the light beams until the target of the image and the target of another image carried by another of the light beams are seen by the person with the same vertical position in the displayed images on the retina of the eye and, wherein adapting the size of the target in each image comprises: - adapting a size of the target of an image carried by one of the light beams in a horizontal direction until the target of the image and the target of another image carried by another of the light beams are seen by the person touching each other in the horizontal direction in the displayed images on the retina of the eye; - adapting a size of the target of an image carried by one of the light beams in a vertical direction until the target of the image and the target of another image carried by another of the light beams are seen by the person touching each other in the vertical direction in the displayed images on the retina of the eye. - adapting a size of the target of an image carried by one of the light beams in a horizontal direction until the target of the image and the target of another image carried by another of the light beams are seen by the person touching each other in the horizontal direction in the displayed images on the retina of the eye; - adapting a size of the target of an image carried by one of the light beams in a vertical direction until the target of the image and the target of another image carried by another of the light beams are seen by the person touching each other in the vertical direction in the displayed images on the retina of the eye.