Vision 2 Flashcards
what are the roles of intrinsic muscles?
control pupil diameter & helps alter lens curvature to enable us to see near objects
what are the roles of extrinsic muscles?
move the eye
what are the 6 extrinsic ocular muscles that move the eye?
Medial rectus (MR) Lateral rectus (LR) Inferior rectus (IR) Superior rectus (SR) Superior Oblique (SO) Inferior Oblique (IO)
what are the actions of MR?
Adduction
what are the actions of LR?
Abduction
what are the actions of SR?
Elevation
Adduction
Intorsion
what are the actions of IR?
Depression
Adduction
Extorsion
what are the actions of SO?
Intorsion
Depression
Abduction
what are the actions of IO?
Extorsion
Elevation
Abduction
what do you look for in right third nerve palsy?
Drooping eyelid
Eye can move only laterally (and slightly down)
what do you look for in left forth nerve palsy?
Eye moving up when adducted
what do you look for in abducent (6th) nerve palsy?
Eye being adducted
Eye not able to abduct
what is Strabismus?
squint-Misalignment of the eyes
what are the 2 different types of squint?
Esotropia (manifest convergent squint)
Exotropia (manifest divergent squint)
what is ambylyopia?
(lazy eye) where brain supresses the image of one eye leading to poor vision in that eye without any pathology (correctable in early years using eye patches to stimulate the “lazy” eye to work)