What is "image purkinje"

Image \Im"age\ ([i^]m"[asl]j; 48), n. [F., fr. L. imago, imaginis, from the root of imitari to imitate. See Imitate, and cf. Imagine.]

1. An imitation, representation, or similitude of any person, thing, or act, sculptured, drawn, painted, or otherwise made perceptible to the sight; a visible presentation; a copy; a likeness; an effigy; a picture; a semblance.

   Even like a stony image, cold and numb.
   --Shak.

   Whose is this image and superscription?
   --Matt. xxii. 20.

   This play is the image of a murder done in Vienn

   1. 
      --Shak.

      And God created man in his own image.
      --Gen. i. 27.

2. Hence: The likeness of anything to which worship is paid; an idol.
   --Chaucer.

   Thou shalt not make unto thee any graven image, . . . thou shalt not bow down thyself to them.
   --Ex. xx. 4, 5.

3. Show; appearance; cast.

   The face of things a frightful image bears.
   --Dryden.

4. A representation of anything to the mind; a picture drawn by the fancy; a conception; an idea.

   Can we conceive Image of aught delightful, soft, or great?
   --Prior.

5. (Rhet.) A picture, example, or illustration, often taken from sensible objects, and used to illustrate a subject; usually, an extended metaphor.
   --Brande & C.

6. (Opt.) The figure or picture of any object formed at the focus of a lens or mirror, by rays of light from the several points of the object symmetrically refracted or reflected to corresponding points in such focus; this may be received on a screen, a photographic plate, or the retina of the eye, and viewed directly by the eye, or with an eyeglass, as in the telescope and microscope; the likeness of an object formed by reflection; as, to see one's image in a mirror.

   Electrical image. See under Electrical.

   Image breaker, one who destroys images; an iconoclast.

   Image graver, Image maker, a sculptor.

   Image worship, the worship of images as symbols; iconolatry distinguished from idolatry; the worship of images themselves.

   Image Purkinje (Physics), the image of the retinal blood vessels projected in, not merely on, that membrane.

   Virtual image (Optics), a point or system of points, on one side of a mirror or lens, which, if it existed, would emit the system of rays which actually exists on the other side of the mirror or lens.
   --Clerk Maxwell.