Abstract: A contour prism progressive lens has a position dependent optical power and a position dependent horizontal prism, and a distance-vision reference point and a near-vision reference point. It is characterized by a coordinate system with its vertical axis running through the distance-vision reference point and has an optical power at the near-vision power reference point that exceeds the optical power at the distance-vision reference point by a value between 0.25 diopter and 1.0 diopter. The horizontal prism on the vertical axis at a vertical coordinate of the near-vision reference point differs from the horizontal prism at the distance-vision reference point by more than 0.2 prism diopter base-in; and the optical power along a horizontal crosscut of the contour prism progressive lens through the near-vision reference point has a broad maximum where the region where the optical power is at least 85% of its peak is at least 5 mm wide.

Abstract: A contour prism lens, having a position dependent optical power and a position dependent horizontal prism, and having a distance-vision reference point and a near-vision reference point, the contour prism lens being characterized by a coordinate system with its vertical axis running through the distance-vision reference point, wherein: the optical power at the near-vision reference point exceeds the optical power at the distance-vision reference point by less than 0.5 diopter; the horizontal prism on the vertical axis at a vertical coordinate of the near-vision reference point differs from the horizontal prism at the distance-vision reference point by more than 0.2 prism diopter base-in; and the optical power along a horizontal crosscut of the contour prism lens through the near-vision reference point has a power plateau, where the optical power remains within a 0.1 diopter wide range throughout a horizontal region at least 5 mm wide, comprising the near-vision reference point.

Abstract: A method for determining a binocular dynamic alignment can include the following steps: causing a patient to gaze at a starting target with a left eye and a right eye, with a display; shifting the target in a first direction by a first target shift angle at a first target shift time, with the display; measuring a first dynamic alignment differential between the left eye and the right eye acquiring the first-shifted target, with an eye tracker; shifting the first-shifted target in a second direction at a second target shift time, with the display; measuring a second dynamic alignment differential between the left eye and the right eye acquiring the second-shifted target with the eye tracker; determining an average dynamic alignment differential from the first dynamic alignment differential and the second alignment differential, with a computer; and determining a prescription prism to reduce the average dynamic alignment differential.

Abstract: A method to determine a binocular alignment includes measuring a disassociated phoria of a patient at a first simulated distance by presenting fusible images including targets with a first parallax corresponding to the first simulated distance, using a headset stereo display at a screen distance; presenting non-fusible images by presenting the target for a first eye with the first parallax and presenting a disassociated targetless image for a second eye, and measuring the disassociated phoria in response to the presenting of non-fusible images, using an eye tracker of the headset; and determining a vergence of the patient at the first simulated distance by presenting fusible images for the first and second eyes with the first parallax, corrected with the measured disassociated phoria; measuring an associated phoria in response to the presenting of fusible images; and determining the vergence as a combination of the disassociated phoria and the associated phoria.