Unit 6 Flashcards
Benefits of binocular vision
Single vision - no “double vision”
Stereo vision - depth perception
Increase field of vision
Compensation for blind spot
Fixation
Image on fovea
Fixation reflexes to keep image on fovea
Fusion
Single image formed with images from both eyes
Diplopia
2 images are perceived, one from each eye
Lack of fusion (double vision)
Suppression
The brain ignores one of the images during diplopia
Amblyopia
Vision loss due to prolonged suppression in childhood
What does BCVA stand for
Best corrected visual acuity
Saccades
Front lobe
Fast movement that keep the image on the fovea
Smooth pursuits
Parietal-occipital region plus other areas of brain
Slow movements of the eyes to follow an object
Ductions
Monocular (abduction, addiction, supraduction, infraduction, intorsion and extortion
Versions
Binolcular
Dextroversion
Leveoversion
Supraversion
Infraversion
Vergences
Binocular; towards or away from eachother
Convergence; both eyes looking towards eachother
Divergence; both eyes look away from eachother
6 muscles
Superior rectus
Inferior rectus
Medial rectus
Lateral rectus
Superior oblique
Inferior oblique
Which muscle is used for elevation
Superior rectus
Which muscle is used for depression
Inferior rectus
What muscle is used for adduction
Medial rectus
What muscle is used for abduction
Lateral rectus
What muscle is used for intorsion
Superior oblique
What muscle is used for extortion
Inferior oblique
Yoke muscle
Muscles from each eye that work together to move eyes together
Ex; LR and MR are yoke muscles , they both equally move the eye laterally or medially
Herings law or equal innervation
When a muscle in one eye is sent a message to move; the yoke muscle in the other eye receives equal innervation
The message is the same to the yoke muscle
Sherringtons law and reciprocal innervation
When a signal is sent to one muscle to contract the opposing muscle for that eye is sent a signal to relax
Talking about one eye itself. It allows one muscle to contact while the other one relaxes. If two muscles are being pulled in opposite ways the eye won’t be able to move
Lateral rectus
Abduction
Medial rectus
Adduction