The Collaborative International Dictionary of English v.0.48:

Eye \Eye\ ([imac]), n. [OE. eghe, eighe, eie, eye, AS. e['a]ge;
   akin to OFries. [=a]ge, OS. [=o]ga, D. oog, Ohg. ouga, G.
   auge, Icel. auga, Sw. ["o]ga, Dan. ["o]ie, Goth. aug[=o]; cf.
   OSlav. oko, Lith. akis, L. okulus, Gr. 'o`kkos, eye, 'o`sse,
   the two eyes, Skr. akshi. [root]10, 212. Cf. Diasy,
   Ocular, Optic, Eyelet, Ogle.]
   1. The organ of sight or vision. In man, and the vertebrates
      generally, it is properly the movable ball or globe in the
      orbit, but the term often includes the adjacent parts. In
      most invertebrates the eyes are immovable ocelli, or
      compound eyes made up of numerous ocelli. See Ocellus.
      Description of illustration: a b Conjunctiva; c Cornea; d
      Sclerotic; e Choroid; f Cillary Muscle; g Cillary Process;
      h Iris; i Suspensory Ligament; k Prosterior Aqueous
      Chamber between h and i; l Anterior Aqueous Chamber; m
      Crystalline Lens; n Vitreous Humor; o Retina; p Yellow
      spot; q Center of blind spot; r Artery of Retina in center
      of the Optic Nerve.
      [1913 Webster]

   Note: The essential parts of the eye are inclosed in a tough
         outer coat, the sclerotic, to which the muscles moving
         it are attached, and which in front changes into the
         transparent cornea. A little way back of cornea, the
         crystalline lens is suspended, dividing the eye into
         two unequal cavities, a smaller one in front filled
         with a watery fluid, the aqueous humor, and larger one
         behind filled with a clear jelly, the vitreous humor.
         The sclerotic is lined with a highly pigmented
         membrane, the choroid, and this is turn is lined in the
         back half of the eyeball with the nearly transparent
         retina, in which the fibers of the optic nerve ramify.
         The choroid in front is continuous with the iris, which
         has a contractile opening in the center, the pupil,
         admitting light to the lens which brings the rays to a
         focus and forms an image upon the retina, where the
         light, falling upon delicate structures called rods and
         cones, causes them to stimulate the fibres of the optic
         nerve to transmit visual impressions to the brain.
         [1913 Webster]

   2. The faculty of seeing; power or range of vision; hence,
      judgment or taste in the use of the eye, and in judging of
      objects; as, to have the eye of a sailor; an eye for the
      beautiful or picturesque.
      [1913 Webster]

   3. The action of the organ of sight; sight, look; view;
      ocular knowledge; judgment; opinion.
      [1913 Webster]

            In my eye, she is the sweetest lady that I looked
            on.                                   --Shak.
      [1913 Webster]

   4. The space commanded by the organ of sight; scope of
      vision; hence, face; front; the presence of an object
      which is directly opposed or confronted; immediate
      presence.
      [1913 Webster]

            We shell express our duty in his eye. --Shak.
      [1913 Webster]

            Her shell your hear disproved to her eyes. --Shak.
      [1913 Webster]

   5. Observation; oversight; watch; inspection; notice;
      attention; regard. "Keep eyes upon her." --Shak.
      [1913 Webster]

            Booksellers . . . have an eye to their own
            advantage.                            --Addison.
      [1913 Webster]

   6. That which resembles the organ of sight, in form,
      position, or appearance; as:
      (a) (Zo["o]l.) The spots on a feather, as of peacock.
      (b) The scar to which the adductor muscle is attached in
          oysters and other bivalve shells; also, the adductor
          muscle itself, esp. when used as food, as in the
          scallop.
      (c) The bud or sprout of a plant or tuber; as, the eye of
          a potato.
      (d) The center of a target; the bull's-eye.
      (e) A small loop to receive a hook; as, hooks and eyes on
          a dress.
      (f) The hole through the head of a needle.
      (g) A loop forming part of anything, or a hole through
          anything, to receive a rope, hook, pin, shaft, etc.;
          as, an eye at the end of a tie bar in a bridge truss;
          an eye through a crank; an eye at the end of rope.
      (h) The hole through the upper millstone.
          [1913 Webster]

   7. That which resembles the eye in relative importance or
      beauty. "The very eye of that proverb." --Shak.
      [1913 Webster]

            Athens, the eye of Greece, mother of arts. --Milton.
      [1913 Webster]

   8. Tinge; shade of color. [Obs.]
      [1913 Webster]

            Red with an eye of blue makes a purple. --Boyle.
      [1913 Webster]

   By the eye, in abundance. [Obs.] --Marlowe.

   Elliott eye (Naut.), a loop in a hemp cable made around a
      thimble and served.

   Eye agate, a kind of circle agate, the central parts of
      which are of deeper tints than the rest of the mass.
      --Brande & C.

   Eye animalcule (Zo["o]l.), a flagellate infusorian
      belonging to Euglena and related genera; -- so called
      because it has a colored spot like an eye at one end.

   Eye doctor, an opthalmologist or optometrist; -- formerly
      called an oculist.

   Eye of a volute (Arch.), the circle in the center of
      volute.

   Eye of day, Eye of the morning, Eye of heaven, the sun.
      "So gently shuts the eye of day." --Mrs. Barbauld.

   Eye of a ship, the foremost part in the bows of a ship,
      where, formerly, eyes were painted; also, the hawser
      holes. --Ham. Nav. Encyc.

   Half an eye, very imperfect sight; a careless glance; as,
      to see a thing with half an eye; often figuratively.
      "Those who have but half an eye." --B. Jonson.

   To catch one's eye, to attract one's notice.

   To find favor in the eyes (of), to be graciously received
      and treated.

   To have an eye to, to pay particular attention to; to
      watch. "Have an eye to Cinna." --Shak.

   To keep an eye on, to watch.

   To set the eyes on, to see; to have a sight of.

   In the eye of the wind (Naut.), in a direction opposed to
      the wind; as, a ship sails in the eye of the wind.
      [1913 Webster]

WordNet (r) 3.0 (2006):

eye doctor
    n 1: a medical doctor specializing in the diagnosis and
         treatment of diseases of the eye [syn: ophthalmologist,
         eye doctor, oculist]