vocab

• accommodation

  normal adjustment of the eye to focus on objects from far to near

  • ciliary body adjusts the lens (rounding it) and pupil constricts
• anterior chamber

  area behind the cornea and in front of the lens and iris

  • contains aqueous humor
• aqueous humor 


  fluid produced by the ciliary body and found in the anterior chamber
• biconvex


  two round surfaces (lens)
• choroid


  middle, vascular layer of the eye between retina and sclera
• ciliary body 


  structure surrounding the lens that connects the iris to the choroid
• cone

  photoreceptor cell in the retina that transforms light energy into a nerve impulse

  • color and central vision
• conjunctiva


  delicate membrane lining the eyelids and covering the eyeball up to the cornea
• cornea


  fibrous transparent layer of clear tissue that extends over the anterior portion of eye
• fovea centralis


  tiny depression in the retina that is region of clearest vision
• fundus of the eye


  posterior, inner part of the eye (ophthalmoscope)
• iris


  pigmented layer than opens and closes to allow light in
• lens


  transparent, biconvex body behind the pupil

  • bends light rays to bring them into focus on retina
• macula


  small oval region near the optic disc and contains fovea centralis
• optic chiasm


  where optic nerve fibers cross in the brain
• optic disc 


  region at the back of the eye where the optic nerve meets the retina

  • blind spot
• optic nerve 


  cranial nerve carrying impulse from retina to the brain (cerebral cortex)
• refraction


  bending of the light rays by the cornea, lens, and fluids of the eye to bring the rays into focus on the retina
• retina


  light-sensitive nerve cell layer containing photoreceptor cells
• rod


  photoreceptor cell of the retina essential for vision in low light and for peripheral vision
• sclera


  tough, white outer coat of the eye
• thalamus


  relay center of the brain
• vitreous humor


  soft, jelly like material behind the lens in the vitreous chamber

  • maintain shape of eye