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  2. Pupil function - Wikipedia

    en.wikipedia.org/wiki/Pupil_function

    The pupil function or aperture function describes how a light wave is affected upon transmission through an optical imaging system such as a camera, microscope, or the human eye. More specifically, it is a complex function of the position in the pupil [ 1 ] or aperture (often an iris ) that indicates the relative change in amplitude and phase ...

  3. Entrance pupil - Wikipedia

    en.wikipedia.org/wiki/Entrance_pupil

    The entrance pupil is the image of the aperture stop viewed from the front of the optical system and here it is a virtual image. Chief rays and marginal rays determine the location and the size of the entrance pupil, respectively. A camera lens adjusted for large and small aperture. The visible opening is the entrance pupil of the lens.

  4. Astigmatism (optical systems) - Wikipedia

    en.wikipedia.org/wiki/Astigmatism_(optical_systems)

    The image at the tangent focus is a short line, oriented in the direction of the sagittal plane; images of circles centered on the optic axis, or small lines tangential to such circles, will be sharp in this focal plane. The image at the sagittal focus is a short line, oriented in the direction of the tangential plane; images of spokes ...

  5. Exit pupil - Wikipedia

    en.wikipedia.org/wiki/Exit_pupil

    The exit pupil is an image of the aperture made by the optics following it; divergent rays from each point in the aperture plane come together again in the exit pupil. To use an optical instrument, the entrance pupil of the viewer's eye (the image of the anatomical pupil as seen through the cornea ) must be aligned with and be of similar size ...

  6. Human eye - Wikipedia

    en.wikipedia.org/wiki/Human_eye

    The vestibulo-ocular reflex is a reflex eye movement that stabilizes images on the retina during head movement by producing an eye movement in the direction opposite to head movement in response to neural input from the vestibular system of the inner ear, thus maintaining the image in the centre of the visual field. For example, when the head ...

  7. Pupillary distance - Wikipedia

    en.wikipedia.org/wiki/Pupillary_distance

    Distance PD is the separation between the visual axes of the eyes in their primary position, as the subject fixates on an infinitely distant object. [2] Near PD is the separation between the visual axes of the eyes, at the plane of the spectacle lenses, as the subject fixates on a near object at the intended working distance. [3]

  8. Accommodation reflex - Wikipedia

    en.wikipedia.org/wiki/Accommodation_reflex

    Light from a single point of a distant object and light from a single point of a near object being brought to a focus. The accommodation reflex (or accommodation-convergence reflex) is a reflex action of the eye, in response to focusing on a near object, then looking at a distant object (and vice versa), comprising coordinated changes in vergence, lens shape (accommodation) and pupil size.

  9. Telecentric lens - Wikipedia

    en.wikipedia.org/wiki/Telecentric_lens

    An image-space telecentric lens has the exit pupil (the image of the aperture stop formed by optics after it) at infinity and produces images of the same size regardless of the distance between the lens and the film or image sensor. This allows the lens to focus light from an object or sample to different distances without changing the size of ...