In fanfiction, why does Hermione have red eyes?

Maybe it's just a creative choice by the author to give her a unique trait.

The reason why his eyes were red was because he was a descendant of the Light Emperor's Lin Clan and had the ability to see red. This red-eyed ability allowed Shouta to instantly burst forth with great strength, speed, and agility. Furthermore, Shue's red eyes were not a characteristic of the demon race, but an inheritance from the Blood Eye Clan, where the Lin family was located.

Owl's have big eyes to help them see well at night when they hunt. Their large eyes allow them to gather more light in the dark.

Owl's have big eyes to help them see better at night. Their eyes are adapted for low light conditions.

Xiao Zhan had auspicious phoenix eyes. Many articles pointed out that Xiao Zhan's eye shape belonged to the Auspicious Phoenix Eye, with a long eye crack and slightly upturned eyes. Although some people classified the Auspicious Phoenix Eyes and the Red Phoenix Eyes as the same series, the style of the Auspicious Phoenix Eyes was more varied. It was not like the Red Phoenix Eyes, where the end of the eye was obviously upturned. Instead, the slightly upturned arc reduced the strength and made it more amorous. Therefore, according to the information provided, Xiao Zhan had auspicious phoenix eyes.

Xiao Zhan had auspicious phoenix eyes. Many articles pointed out that Xiao Zhan's eye shape belonged to the Auspicious Phoenix Eye, with a long eye crack and slightly upturned eyes. Although some people classified the Auspicious Phoenix Eyes and the Red Phoenix Eyes as the same series, the style of the Auspicious Phoenix Eyes was more varied, unlike the Red Phoenix Eyes, which had an obvious upturned end. Therefore, Xiao Zhan's eyes were classified as auspicious phoenix eyes.

One possible reason could be that in the fanfiction, Hermione might be more focused on her studies or magical research. She has always been an academic at heart, and perhaps she feels that a sexual relationship with Ron would distract her from her intellectual pursuits.

The reason why Wen Zhong had three eyes was because he had cultivated for thousands of years and gradually comprehended the laws of the Heavenly Dao, thus obtaining the power of the Heavenly Eye. According to legend, Wen Zhong was born with a third eye. It had already existed when he was born. His third eye was known as the Eye of Divine Power. It could distinguish between good and evil, and help him become an important official of the Shang Dynasty. Some legends said that Wen Zhong's third eye came from Goddess Nüwa, and humans had a third divine eye to begin with. They could only open it by cultivating the Great Dao. In short, Wen Zhong's third eye was the result of his cultivation and birth. It had a special ability.

Well, in some fanfictions, Hermione might hate Bella because their personalities are so different. Hermione is studious, logical, and a fighter for justice. Bella, on the other hand, is often portrayed as more passive and overly focused on her romantic relationships. Their different values and ways of approaching life could lead to Hermione's dislike of her in fanfiction.

Maybe Lily has a very different view of the characters. She might think the fanfiction misrepresents Hermione in some way that she doesn't like.