ouka september

Red-Eyes MacadamiaChoco's original character. A oni girl who has red eyes, pink-white gradient hair and curved horns. She wears black thighhighs.

She has no sight in her right eye and her right horn is broken. She often wears a blade-like prosthetic horn. (See Danbooru post #1203121)
Sometimes her eyes look like heterochromia, however it describes her blind right eye, or it's a glowing eye as a magic effect. See also the artist's tweet.