One possible fanfiction could be that Harry Potter is kidnapped by a dark wizard who has some strange power that makes Harry squint. Maybe this wizard is trying to use Harry's unique connection to Voldemort for some dark ritual. Harry has to use his wits and the few spells he can manage while squinting to try and escape.
The plot could be that Harry is kidnapped by a vengeful Death Eater who survived the war. This Death Eater wants to use Harry to bring back Voldemort in a new form. The squinting part could be due to a curse the Death Eater placed on Harry to limit his vision and thus his ability to escape. Harry has to rely on his other senses and his past experiences to outwit the Death Eater.
In many fanfictions, Harry Potter squinting at Voldemort could be a sign of intense focus. It might be that Harry is trying to read Voldemort's next move, or perhaps he's looking for some sign of weakness. For example, in some stories, Harry's squinting could be related to his newfound magical abilities that he's using to analyze Voldemort's magic signature.
It could mean a fan - made story (fanfiction) where Harry Potter is looking closely or suspiciously at a snake. Maybe in this fanfiction, the snake has some special significance, like being related to Slytherin or having some kind of magical power that Harry is trying to figure out by squinting at it.
There could be a fanfiction where Harry is studying in the library with his broken glasses. He's squinting hard to read the old, faded texts. Hermione notices and offers to help him fix his glasses with a spell she's been researching. But Harry refuses at first, wanting to do it on his own. This creates a bit of tension between them, and as they argue, Ron comes in and tries to mediate. It could be a comical and character - driven fanfiction scenario.
He could be squinting because he's trying to read Shacklebolt's expression carefully. Harry has been through a lot and has learned to be cautious. Maybe he's looking for any sign of deception or unease in Shacklebolt's face.
It might also indicate a newfound curiosity. Fanfiction often takes characters in different directions. Harry could be squinting at Malfoy because he's starting to see a different side of him. Maybe he's noticed something that makes him think Malfoy isn't all bad, and the squint is his way of trying to understand this new Malfoy better.
Maybe it's a fanfiction set in an alternate magical universe. Here, Draco might have a more complex role in Harry's kidnapping, and the glasses issue adds an extra layer of drama.
It could be that Harry has noticed some strange behavior from Malfoy. For instance, Malfoy might be acting secretively around certain areas of Hogwarts. Harry's squinting is his way of observing Malfoy closely to find out what he's hiding.
One possible plot could be that Felicity, a smart and squinting glasses - wearing woman, is kidnapped because she has some important information. Maybe she's a scientist who has made a breakthrough discovery and some bad guys want to use it for their own gain. Her friends then start a search mission to rescue her.