The plot could involve Voldemort using Harry as a pet to send a message to the wizarding world. Without his glasses, Harry is a symbol of his power over the so - called 'Chosen One'. Voldemort might parade Harry around, showing how he has defeated and humiliated him. But Harry, being Harry, uses this situation to learn more about Voldemort's weaknesses. He observes Voldemort's lair, the way he interacts with his Death Eaters, and starts to formulate a plan to not only escape but also to bring down Voldemort once and for all.
Maybe in this fanfiction, Voldemort has a change of heart after making Harry his pet. Without his glasses, Harry appears more helpless, and this could stir some long - forgotten emotions in Voldemort. He starts to see Harry not just as an enemy but as someone he can manipulate in a different way. He could try to groom Harry to be on his side, using a combination of threats and false kindness. Harry, on the other hand, is constantly thinking of how to turn the tables and get back to his friends and the fight against the Dark Lord.
The fanfiction could explore a scenario where Harry's glasses are taken away as a way to break his spirit. Voldemort, having Harry as his pet, might want to completely subdue him. Without his glasses, Harry has to navigate a blurry world. This could lead to some interesting interactions with other characters. For example, Hermione might try to find a magical way to restore Harry's vision or at least give him some form of sight assistance without glasses. Ron, on the other hand, could be conflicted about whether to help Harry escape Voldemort's clutches or if he should follow Voldemort's orders as well since Harry seems so different without his glasses.
In some fanfictions, Voldemort's pet might be used as a symbol of his power and evil. Harry's glasses, on the other hand, are an iconic part of his character. The combination could be used to create a unique plot. For example, Voldemort's pet might steal Harry's glasses to disrupt his vision and thus his ability to fight. It could also be a more symbolic connection, like the pet representing Voldemort's hold over Harry's life, and the glasses being a symbol of Harry's identity that Voldemort wants to break.
Harry would likely be defiant at first. Even without his glasses, he has his inner strength. He would probably try to resist Voldemort's every command and look for opportunities to escape or fight back.
One possible plotline could be that Voldemort's pet somehow steals Harry's glasses as a way to taunt him. This could lead to Harry going on a quest to retrieve them, facing various dark magic obstacles along the way.
It could be that Voldemort's pet Harry is actually a form of psychological warfare for Voldemort. He wants to break Harry's spirit completely. However, Harry uses this situation to his advantage. He befriends some of the dark creatures that Voldemort has around his lair, and with their help, he manages to create chaos and confusion, which in turn gives the Order of the Phoenix an opportunity to strike at Voldemort.
It could be that the pet is magically attracted to the glasses. Maybe the glasses have a certain charm or power that the pet senses, and it tries to steal them to bring back to Voldemort. For example, if the glasses can see through certain dark magic disguises, Voldemort would want to get his hands on them through his pet.
The pet could try to break Harry's glasses. Since Voldemort hates Harry, his pet might be programmed or trained to destroy things that are important to Harry. The glasses are a very visible and important part of Harry.
One possible plot for a 'Harry Potter in prison without glasses' fanfiction could be that Voldemort or his followers have managed to frame Harry for a serious crime. In prison, without his glasses, Harry is constantly disoriented. He has to learn to adapt quickly. There could be a new character, perhaps a sympathetic prison guard or a fellow inmate who helps him get by. Harry could also discover some hidden magic within the prison walls that he can only access because he is in this vulnerable state without his glasses. This new magic could be the key to his escape and also to defeating Voldemort's plans in the long run.
Well, perhaps in this fanfiction, Harry could be imprisoned by some dark wizards. Without his glasses, he'd be at a great disadvantage, relying more on his other senses and magical instincts. Maybe he uses his Parseltongue ability to communicate with a snake in the cell to help him escape.
In a 'Harry Potter without glasses brawl' fanfiction, it could start during a Quidditch match. Without his glasses, Harry can't see clearly. He thinks an opposing team's player is trying to cheat in a really aggressive way and he jumps into a fight mid - air. This could lead to a huge brawl between the two teams. And the Ministry of Magic might get involved later to sort out the mess.