corner of the eyes, eyesockets
眦 centers on the outer corner of the eye and the surrounding bony socket. It refers to the anatomical corner where the eyelids meet and the eye socket itself.
corner of the eye
眦 combines 目 (eye) with 此, which likely contributes the sound. The character specifically denotes the corner of the eye.
The left side 目 is the eye, and the right side 此 looks like a stop sign with a person beside it. Imagine stopping at the corner of your eye where the eyelid meets the socket.
For セ, picture a sailor saying 'Aye aye, cap'n!' while pointing to the corner of his eye: 'say' -> セ, and the corner of the eye is where the sailor's gaze stops.