The optic nerve represents the connection between the receptor cells of the [[Eye - Anatomy & Physiology#The Wall (retina, uvea and sclera)|retina]] and the [[Forebrain - Anatomy & Physiology|forebrain]]. The optic nerve is a sensory nerve and is composed of '''Special Somatic Afferent fibres'''. The optic nerve passes through the [[Skull and Facial Muscles - Anatomy & Physiology#Sphenoid Bone (os_sphenoidale)|'''optic chiasm''']] which is an area of the ventral brain where both optic nerves run in a medial direction and eventually decussate. The optic nerve runs through the [[Skull and Facial Muscles - Anatomy & Physiology#Sphenoid Bone (os_sphenoidale)|'''optic canal''']].
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The optic nerve represents the connection between the receptor cells of the [[Eye - Anatomy & Physiology#The Wall (retina, uvea and sclera)|retina]] and the [[Forebrain - Anatomy & Physiology|forebrain]]. The optic nerve is a sensory nerve and is composed of '''Special Somatic Afferent fibres'''. The optic nerve passes through the [[Skull and Facial Muscles - Anatomy & Physiology#Sphenoid Bone (os_sphenoidale)|'''optic chiasm''']] which is an area of the ventral brain where both optic nerves run in a medial direction and eventually decussate. In the horse, approximately 85-88% of fibres decussate. The optic nerve runs through the [[Skull and Facial Muscles - Anatomy & Physiology#Sphenoid Bone (os_sphenoidale)|'''optic canal''']]. Fibres then go to geniculate nucleus then impulses travel via the optic radiations to occipital lobe for visual processing. The ganglion cells also project to pretectal nuclei for modulation of parasympathetic tone to the iris and rostral colliculi for the startle response.