How to test action of superior oblique muscle of your eye?

Hello everyone,how are u all?hope you are all fine and safe and healthy at home.Today i would like to share a thing that i learned.
Every eye of humanbeing has 7 extraocular muscles and i would like to tell about one muscke in brief manner and i.e.,the superior oblique muscle.there are 2 superior oblique muscles one in each eye.we all know that every muscle has some action to do and here superior oblique action is Depression in adduction adducted position of eye.

So if we want to test its action whether it is intact or not.then we have to ask them(on whom we are testing) to look at nose.like this image below

(image source)

And normal people will do like the above picture perfectly.

Superior oblique muscle is supplied by 4th cranial nerve which is trochlear nerve.so if there is any injury to this nerve or muscle.then patient can perform this ocular movement(due to loss of its movement).this movement( depression in adducted position) is restricted

So we can identify by this method.

Thanks for reading,
Hope it will be some what useful.
Yours @summisimeon