A scenario could be that Naruto is in a diplomatic meeting. He covers his eyes to avoid being influenced by any mind - control or genjutsu that might be subtly used by the other parties. This shows his wariness and also his growth in being able to sense and protect himself from such threats in the political arena of the ninja world.
Another reason could be for disguise. Naruto might be in a situation where he needs to hide his identity. By covering his eyes, which are a very recognizable feature of his, he can make it more difficult for others to figure out who he is. This could be especially important if he is in enemy territory or trying to infiltrate a group secretly.
One possible reason could be that his eyes hold a special power that he doesn't want others to discover easily. For example, it might be a new type of Sharingan or a unique ability related to his Uzumaki heritage that he needs to keep secret to protect himself or those around him.
He could use a simple cloth. Just a plain piece of fabric wrapped around his face, like a ninja in a hurry would do. This is a very basic and practical way that is often seen in traditional ninja - themed stories.
His relationships with his friends might become stronger. Since he can see more clearly with his god eyes, he can better protect them. His friends would trust him more knowing he has this extra power to keep them safe.
His friends might react with shock and confusion. They might not understand why he has been hiding this from them, and it could cause a rift in their relationships until he explains the reasons behind it. For example, some friends might feel betrayed that he didn't trust them enough to share this secret.
Perhaps he's trying to protect himself from some kind of danger. There could be an enemy who is looking for him and by covering his face, he can avoid being detected easily. It could also be a part of a new jutsu or power he has discovered where covering his face is necessary for its activation or control.
Well, if Naruto had 3 eyes in fanfiction, his visual perception would be greatly enhanced. He could potentially have a wider field of vision, like being able to see in more directions simultaneously. This might give him an edge in battle, as he could detect enemies coming from unexpected angles more easily.
He might rely more on his other senses like hearing and smell. Just like real - world blind people can develop enhanced other senses, Naruto could use his chakra to sense the environment more acutely.
It could be a new character created specifically for the fanfic. Maybe a rogue ninja from a far - off land who has a vendetta against Naruto. This antagonist might be after Naruto's power or trying to stop him from achieving a certain goal.