Hering's law of equal innervation

Now to study this law, we need to know clinical function diagram of eye muscles.

So according to this diagram,

Right SR is responsible for elevating right eye to right side.
Similarly, Left IO is responsible for elevating left eye to right side.

Since both the muscles are performing same action on two different eyes using two different muscles they are called yoke muscles of each other.
This is Hering's law of equal innervation.

Now, here is a trick to solve problem without looking into the diagram:

Right gets converted to Left.
S (Superior) gets converted to I (Inferior)
O (Oblique) gets converted to R (Rectus)

So the mnemonic for remembering muscle change is

ROSI (You can remember it as ROSS from friends!)
R gets converted to O.
S gets converted to I.

-Demotional bloke