outside the corner of the eye
眥 refers specifically to the outer corner of the eye, the area where the upper and lower eyelids meet laterally.
眥 combines 目 (eye) with 此, which likely contributes the sound. The character is used to denote the outer corner of the eye.
The eye 目 is below 此, like a mark pointing to the outer corner of the eye.
For セ, imagine saying 'say' while pointing to the outer corner of your eye: 'say' -> セ.
glaring with hatred; glare filled with hatred