• The sensory organ of vision.
  CDISC Terminology
  Clinical Data Interchange Standards Consortium (CDISC), 2021
• The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2021
• The organ of sight or vision.
  NCI Thesaurus
  U.S. National Cancer Institute, 2021
• (eyeball) Organ with organ cavity which is connected to the optic nerve. Examples: There are only two eyeballs, the right and the left eyeballs..
  Digital Anatomist
  University of Washington, 2003
• (eyeball) Organ with organ cavity, each instance of which is connected to some optic nerve. Examples: There are only two eyeballs, the right and the left eyeballs.
  Foundational Model of Anatomy
  University of Washington, 2017
• Human eye, in humans, specialized sense organ capable of receiving visual images, which are then carried to the brain. The eye is protected from mechanical injury by being enclosed in a socket, or orbit, which is made up of portions of several of the bones of the skull to form a four-sided pyramid...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2020
• Eyeball, spheroidal structure containing sense receptors for vision, found in all vertebrates and constructed much like a simple camera. The eyeball houses the retina--an extremely metabolically active layer of nerve tissue made up of millions of light receptors (photoreceptors)--and all of the...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2020