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  2. Photoreceptor cell - Wikipedia

    en.wikipedia.org/wiki/Photoreceptor_cell

    Distribution of rods and cones along a line passing through the fovea and the blind spot of a human eye [7] Most vertebrate photoreceptors are located in the retina. The distribution of rods and cones (and classes thereof) in the retina is called the retinal mosaic. Each human retina has approximately 6 million cones and 120 million rods. [8]

  3. Layer of rods and cones - Wikipedia

    en.wikipedia.org/wiki/Layer_of_rods_and_cones

    The elements composing the layer of rods and cones (Jacob's membrane) in the retina of the eye are of two kinds, rod cells and cone cells, the former being much more numerous than the latter except in the macula lutea. Jacob's membrane is named after Irish ophthalmologist Arthur Jacob, who was the first to describe this nervous layer of the ...

  4. Rod cell - Wikipedia

    en.wikipedia.org/wiki/Rod_cell

    Rod cells are photoreceptor cells in the retina of the eye that can function in lower light better than the other type of visual photoreceptor, cone cells. Rods are usually found concentrated at the outer edges of the retina and are used in peripheral vision. On average, there are approximately 92 million rod cells (vs ~6 million cones) in the ...

  5. Visual phototransduction - Wikipedia

    en.wikipedia.org/wiki/Visual_phototransduction

    Visual phototransduction is the sensory transduction process of the visual system by which light is detected by photoreceptor cells (rods and cones) in the vertebrate retina.A photon is absorbed by a retinal chromophore (each bound to an opsin), which initiates a signal cascade through several intermediate cells, then through the retinal ganglion cells (RGCs) comprising the optic nerve.

  6. Cone cell - Wikipedia

    en.wikipedia.org/wiki/Cone_cell

    There are about six to seven million cones in a human eye (vs ~92 million rods), with the highest concentration occurring towards the macula and most densely packed in the fovea centralis, a 0.3 mm diameter rod-free area with very thin, densely packed cones. Conversely, like rods, they are absent from the optic disc, contributing to the blind spot.

  7. Visual system - Wikipedia

    en.wikipedia.org/wiki/Visual_system

    With this simple geometrical similarity, based on the laws of optics, the eye functions as a transducer, as does a CCD camera. In the visual system, retinal, technically called retinene 1 or "retinaldehyde", is a light-sensitive molecule found in the rods and cones of the retina.

  8. Blind spot (vision) - Wikipedia

    en.wikipedia.org/wiki/Blind_spot_(vision)

    Distribution of rods and cones along a line passing through the fovea and the blind spot of a human eye [1]. A blind spot, scotoma, is an obscuration of the visual field.A particular blind spot known as the physiological blind spot, "blind point", or punctum caecum in medical literature, is the place in the visual field that corresponds to the lack of light-detecting photoreceptor cells on the ...

  9. External limiting membrane - Wikipedia

    en.wikipedia.org/wiki/External_limiting_membrane

    The external limiting membrane (or outer limiting membrane) is one of the ten distinct layers of the retina of the eye. It has a network-like structure and is situated at the bases of the rods and cones .