Perhaps the girl without glasses has a special ability that she's not fully aware of. The kidnappers, who are part of some sort of secret organization, know about this ability. They kidnap her to study her or use her power for their own purposes. As she's held captive, she starts to discover more about this ability herself and tries to use it to escape.
Another possibility is that a mysterious character in the fanfiction world, who has a soft spot for the girl, finds her lost glasses. He then uses this as a clue to track down where she has been taken. Along the way, he discovers more about the girl's situation and the reasons behind her kidnapping.
One possible fanfiction could be that the girl who was kidnapped was a very shy and nearsighted person. Without her glasses, she could barely see. The kidnapper might have targeted her because of some special ability she unknowingly had. As she was squinting in the dark place where she was held, she started to recall all the mystery novels she had read, trying to find a way to escape using the little she could see and her wits.
There could be a heroic rescue. Maybe her friends or family notice she's missing quickly. They start looking for her and manage to track down the kidnappers. Since she doesn't have her glasses, she has to rely on her other senses like hearing to help her stay alive until she's rescued.
The kidnapper could be a jealous rival. Maybe in the story's setting, there's a competition of some sort, and the girl without glasses is a threat to the rival. So, the rival decides to kidnap her to eliminate the competition.
One possible plot could be that the girl is kidnapped from a place where she left her glasses behind. She is a key figure in a certain event, and the kidnappers want to use her for their own gain. Without her glasses, she struggles to adapt to the new environment at first. However, as time passes, she befriends another captive who helps her get around. Together, they plan an escape and in the process, she discovers that there's more to her kidnapping than she initially thought.
One possibility is that the kidnapper is an ex - partner or an ex - friend who has turned bitter. They might feel betrayed by the girl with glasses in some way and think that kidnapping her is the best way to get back at her. Another likely candidate could be a character from a parallel story or an alternate universe who has some sort of vendetta against the girl. For instance, if there are different factions in the fanfiction world, and the girl with glasses is on one side, someone from the opposing side might kidnap her to gain an advantage. Additionally, it could be a self - proclaimed vigilante who believes the girl is involved in something wrong and takes it upon himself to 'punish' her by kidnapping her.
I'm not sure which specific 'Kidnapped Felicity Squints Without Glasses' fanfiction you're referring to. There could be many different interpretations and stories within that concept. Maybe it's about Felicity being kidnapped while in a situation where she's not wearing her glasses and has to rely on other senses or the help of others to escape.
In this fanfiction, Blurry without glasses might be on a quest to rescue Felicity. Their journey could be filled with obstacles not only because of the danger of the kidnappers but also because of their impaired vision. This could lead to some really intense and exciting scenes as Blurry tries to navigate and find Felicity.
Perhaps the lost glasses are not ordinary glasses at all. They could be from a different world or dimension. Felicity's kidnapping might be part of a larger plot to retrieve the glasses for some dark purpose. The fanfiction could explore how Felicity uses her wits and skills to outsmart the kidnappers and either keep the glasses safe or use them to her advantage. It could also have elements of mystery and suspense as the true nature of the glasses is gradually revealed.