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optic chiasm
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Labeled diagram of a mammalian pituitary gland showing key structures, including the paraventricular and supraoptic nuclei, neurosecretory cells, blood vessels, and pathways for hormone release and blood flow. Diagram showing how visual information from an object enters the left and right eyes, travels along the optic nerves, crosses at the optic chiasma, and reaches the occipital lobes in the brain for image processing. Labeled anatomical diagram of the human brain in sagittal section, medial view, showing internal structures such as the corpus callosum, cerebellum, ventricles, brainstem, and other key regions. Diagram of the human brain highlighting the pineal gland within the endocrine system, with labeled structures including the cerebral cortex, hypothalamus, optic chiasm, pituitary gland, and third ventricle.
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optic chiasm

anatomy
Also known as: optic chiasma
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Labeled diagram of a mammalian pituitary gland showing key structures, including the paraventricular and supraoptic nuclei, neurosecretory cells, blood vessels, and pathways for hormone release and blood flow.
mammalian pituitary gland Elements in a generalized mammalian pituitary gland.

The optic chiasm is an X-shaped structure located on the undersurface of the brain's hypothalamus. It is formed where the optic nerves from each eye meet. At the optic chiasm, approximately half of the nerve fibers from each optic nerve cross over to the opposite side of the brain, while the other half continue on the same side. This crossing is crucial for binocular vision, allowing us to perceive depth. Damage to the optic chiasm can result in specific visual field defects, such as bitemporal hemianopia, where the outer halves of the visual fields in both eyes are affected. This can be caused by conditions like a pituitary tumor pressing on the chiasm.123

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3 Britannica Sources
  1. optic chiasma
  2. optic nerve
  3. visual field defect

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