Step I Help with eye muscles

[Episome]

Hey just a quick question, I've been reviewing how the eye works for step and it looks like different resources are saying different things. My notes from first year seem to indicate that a person looking to his or her lower right will use the superior oblique for the right eye, and inferior rectus for the left eye. It looks like it's switched in First Aid. Which is correct? Any help would be appreciated.

 

[ASM student]

What's the source of the second pic?!!
FA is correct, remember that the common ring from which almost all the EOMs originates lies not only posterior but also medial to the eye globe and as inferior rectus insertion is in the inferior part in the posterior half of the globe it will bring it down and in (medial) which means that the anterior half will be brought out (lateral), you can simulate the movement on a ping ball to imagine how it works.
Edit: it's inserted just anterior to the equator of the eye ball with the same actions though.

 

[Episome]

Thanks so much! School powerpoint lol, last time I go back to those for something.

 

[iBS1972]

.

 

[ASM student]

I would disagree and say the second picture is actually the right one. Remember First Aid will have mistakes.
The reason why is think about CNIII palsy, which leads to the characteristic "down-and-out" eye. This is due to impairment of IO and IR, leaving unopposed leaving unopposed SO, causing a down and out movement of the eye.

Edit: The superior oblique acutally attaches lateral to the axis of rotation.
https://www.intechopen.com/source/html/42401/media/image12.jpeg

Actually, both pictures are correct, but they convey different purposes.
The first one is showing you which muscles are active when you do the CN3,4,6 exams.
The second one is showing you which how the eye would move if you had that muscle only.

Lateral rectus will be spared in CNIII palsy as it's supplied by abducent nerve and it's main action is bringing the eye out that's why you'll see the classic "down and out" with CN III palsy.

Sent from my HUAWEI GRA-L09 using Tapatalk

 

[iBS1972]

Wikipedia actually has a wonderful articles about eye movements and great pictures showing the insertion sites. I encourage you to take a look. Search "eye movements". It also has links to each of the muscles that tells you their function.