Thursday, January 20, 2011

EOM Actions Using Syah's Rule

Do you have problem memorizing Extraocular Muscle Actions before this? If yes, let's apply Syah's Rule. In this post using Syah's Rule , we concern on vertical muscles actions. Why??? Lateral muscles have one action only either abduction for Lateral Rectus and adduction for Medial Rectus.

Vertical muscles have 3 muscle actions named as 1st action, 2nd action and 3rd action or in other words it's controls vertical movement (elevation or depression), torsional movement (extortion or intortion) and lateral movement (adduction or abduction). So many guys..Fenin2..Headache to remember them...

Relax guy, I'm here to make its simple using Syah's Rule..Please refer to the figure above...
  1. The upper muscle in red triangular which are Superior Rectus (SR) and Inferior Oblique (IO) = muscle action is elevation
  2. The lower muscle in green inverse triangular which are Inferior Rectus (IR) and Superior Oblique (SO) = muscle action is depression
  3. All 'S' muscles (Superior Muscle) = muscle action is Intortion
  4. All 'I' muscles (Inferior Muscle) = muscle action is Extortion
  5. All 'O' muscles (Oblique Muscle) = muscle action is Abduction
  6. All 'R' muscles (Rectus Muscle) = muscle action is Adduction 

It is simple, right?...Remember of the Word, Remember of the Action.


  1. I like it..very helpful...patutnya dah lama sy visit this blog..selama ni fenin kepalo saya nak ingat semua ni..Keep up..

    1. Tqvm..everything would be easy if we can apply our rule o simple rule

  2. ..It's simple..the rules are pretty cool..wonderful..
    It’s inspiring me to join Optometry course and your school as well.

    1. Tqvm..for details about our optometry school, you can log on to

  3. Hi,first and foremost let me introduce myself.I am a student studying in NIOS. I have been following your blog for quite awhile. Thanks for all the tips and update with the optometrist undergraduates. Hope to have a join activities with your university someday. Thanks again.

    1. Tqvm for following my blog..feel free to come to our school at Kuantan.

  4. Hope this rule benefit all of you..

    I like a simple thing because

    "A lazy man always think the simplest way to solve any thing" :)



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