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Optic nerve

A. Direct & consensual light reflexes – Pathway


B. Accommodation reflex
When the eyes are directed from a distant object to a near object:
  • Medial recti contracts (Brings convergence)
  • Lens thickens to increase the refractory power by contracting ciliary muscles
  • Pupils constrict to restrict light waves to the thickest central part of the lens

The pathway

C. Corneal reflex : Light touching of the cornea or conjunctive results in blinking of the eye lids
Cornea or Conjunctiva
Ophthalmic branch of the TGN
Main sensory ganglion of the TGN
Internuncial neurons connect with the motor nucleus of the facial nerve on Both sides (Through the medial longitudinal fasciculus)
Facial nerve
Orbicularis oculi of both sides
Closure of the eyelids

D. Visual body reflex


Effects of visual body reflexes
  • Automatic scanning movements of the eyes & head that are made when reading
  • Automatic movements of the eyes, head & neck towards the visual stimulus
  • Protective closing of the eyes & raising arm for protection
Optic nerve Optic  nerve Reviewed by Radiology Madeeasy on August 08, 2010 Rating: 5
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