Perhaps in this fanfiction, Harry is in a cage as part of a magical experiment. Some rogue wizards are trying to study how a wizard's magic is affected without their usual aids, like Harry's glasses. In the cage, Harry discovers new aspects of his magic that he didn't know before. He could start to manipulate the magical energy around him in different ways, even without clear vision, and eventually break free from the cage and confront those who put him there.
It could be part of a magical curse. The curse made him lose his glasses and trapped him in a cage. Maybe it was cast by a jealous student at Hogwarts who wanted to get back at Harry for always being in the spotlight. In the cage, Harry has to figure out how to break the curse and get his glasses back, all while dealing with the limitations of his impaired vision.
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.
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.
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.
The plot could involve Harry using his magic in a different way. Since he can't see clearly, he might have to focus more on wandless magic or non - visual spells. For example, he could be trying to sense the magical energy in the cell to find weak points in the walls or barriers. And perhaps there are other prisoners in the cell with him who he has to interact with, and without his glasses, misidentifying them at first could lead to some interesting plot twists.
One possible plot could be that Harry, without his glasses and drunk, stumbles around Hogwarts in a daze. He might accidentally end up in a restricted area, like the Forbidden Forest. Maybe he has some misadventures with the magical creatures there, all while being in a drunken state and unable to see clearly. His friends would then have to go and find him.
In this fanfiction, Harry without his glasses could be in a situation where he is forced to rely on his friends more when dealing with Horcruxes. His vision impairment without glasses makes it difficult for him to be as independent as he used to be. So, Hermione and Ron play a more crucial role. For example, when they are searching for a Horcrux in a dark and dangerous place, Harry has to trust their descriptions completely. And as they progress, Harry discovers that the Horcruxes are affecting his vision in a magical way, and he has to find a way to break this spell while still trying to destroy the Horcruxes.
One possible plot could be that Harry is captured by some dark wizards who know his power lies in his eyes (with his glasses being a symbol of his clear - sightedness in magic). They cage him up to weaken him, perhaps trying to prevent him from seeing certain magical signs or spells. Without his glasses, he's disoriented at first but then uses his other senses and inner magic strength to start fighting back.
The plot could change significantly. For starters, his initial reaction to the portkey journey and arrival would be different. Instead of quickly taking in the scene, he'd be fumbling around. This could lead to him being left behind by his companions if they're in a hurry. Also, if there's a mystery to solve at the destination, his impaired vision might make him overlook crucial clues that are visible only to those with good eyesight.
Well, perhaps Harry gets his glasses broken during a battle with Death Eaters. In this disordered world without his clear vision, he has to use his magic in different ways. He might use a spell to enhance his other senses, like a super - hearing spell. This would allow him to detect approaching enemies, but it also makes him more sensitive to all the noises in Hogwarts, which can be overwhelming. And he would have to rely on his friends even more to get around and complete tasks.