Laws

  1. Hering’s Law
    • During any conjugate eye movements, equal & simultaneous innervation flows to the yoke muscles. It is true for vergence & version.

  2. Foster Kennedy syndrome
    • Unilateral papilloedema with optic atrophy in the other eye suggestive of frontal lobe tumour or olfactory or sphenoidal meningioma of the opposite side. P.S. : papilloedema never develops in optic nerve which is atrophic.

  3. Pseudo Foster Kennedy syndrome
    • Unilateral papilloedema associated with raised intra cranial pressure due to any cause with pre existing optic atrophy due to any cause on the other side.

  4. Sherington’s Law of reciprocal innervations
    • During any conjugate eye movements, increased innervation to an extra ocular muscle is accompanied by a reciprocal decrease in innervation to its antagonist. It is applicable both to version & vergence. Exception : Duane’s Retraction syndrome : simultaneous contraction of the agonist & antagonist leading to no ocular movement + globe retraction.