Final answer:
The 'SI channel' does not correspond to clearly defined anatomical structures related to the eyes, but the lacrimal apparatus and canthal tendons have defined attachment points near the canthi.
Step-by-step explanation:
The question seems to have a typographical error as 'SI channel' does not correspond to anatomical terms related to the canthi of the eyes or other well-defined structures in the human body.
However, if you are referring to anatomical structures around the eyes such as the lacrimal canals, which are part of the lacrimal apparatus and play a role in tear drainage, they do not directly connect to the canthi but rather start at the lacrimal puncta, located near the inner canthi of each eye, and lead to the lacrimal sacs.
Other structures, like the canthal tendons, attach to the canthi, with the medial canthal tendon attaching at the anterior lacrimal crest near the internal canthus, and the lateral canthal tendon attaching at the Whitnall's tubercle of the zygomatic bone near the external canthus. These intricacies of ocular anatomy are essential for eye movement and function.