Extra Ocular Muscles - For Vision and Eyeball Movement
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Extra Ocular Muscles : Responsible for Vision and Eyeball Movement

Dr.Surya Rao Poodipeddi profile Authored by Dr.Surya Rao Poodipeddi on 22 Apr 2014 - 22:51.
The human eye is a combination of two mechanisms namely the vision and movements of the eyeballs.
Each mechanism is inter-related in that the vision includes central as well as peripheral viewing. The beauty of such a wonderful mechanism lies in the fact that both eyes maintain a perfect synchronization in respect of peripheral vision. If the person wants to see what is in the left side the eyeball moves towards the left and both eyeballs move simultaneously towards that direction. Same is the case in whichever direction the owner of these marvels of creation wishes to see.
There are three ways by which a person can achieve viewing an object. One is to move the entire neck towards the object he wants to see. The other is to turn the whole body towards the object he wants to see. And the third, the most important and commonly utilized mode of viewing is through the movements of the eyeballs towards the object he wants to view without turning either the neck or the body.
The last mechanism of viewing through the movements of the eyeballs is controlled by three pairs of muscles (6 muscles altogether), which are inserted to the sclera of the eyeballs.
What follows is a brief description of these muscles called the extra ocular muscles and their functions including problems they might face and the remedial actions that can be taken wherever possible.
Of the three pairs of the muscles, two pairs are the rectus muscles running straight to the bony orbit of the skull which are orthogonal (symmetrical) to each other and are called The superior rectus (The muscle which lies on the top of the eyeball) the inferior rectus (the one that lies below towards the floor) the medial rectus (the one which lies towards the nasal side of the eyeball) and the lateral rectus (the one which lies away from the nasal side) of the respective eyeball. A further pair of muscles are the oblique muscles called the superior oblique (so called because it pulls the eyeball above and at an angle) and the inferior oblique (which pulls the eyeball downwards obliquely)
These extra ocular muscles rotate the eyeball in the orbits (Orbit is a circular bony cavity in the skull in which the eyeball lies fully protected) and allow the image to be focused at all times on the fovea of the central retina, the structure responsible for vision.
As the names imply each external muscle of the eyeball performs a particular movement of the eyeball, which the muscle of the other eyeball synchronizes perfectly, known as conjugate movements of the eyeballs which are:
  • The medial rectus moves the eye towards the nose.
  • The lateral rectus moves the eye away from the nose.
  • The superior rectus moves the eye up.
  • The inferior rectus moves the eye down.
  • The superior oblique rotates the eye so that the top of the eye moves towards the nose.
  • The inferior oblique rotates the eye so that the top of the eye moves away from the nose.
*Disclaimer: This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.