Well, in 'naruto is blinded fanfic', a frequent theme is the exploration of new abilities. Since he can't rely on his sight anymore, he may develop other skills such as enhanced hearing or a better sense of smell to compensate. Additionally, the theme of perseverance is common. Naruto is a character known for not giving up, and his blindness would be another obstacle for him to overcome. And there's also the theme of change in relationships. His blindness could cause some characters to treat him differently, either with more pity or more respect depending on how the story is written.
One common theme is adaptation. Naruto has to adapt to being blind, whether it's in combat, daily life, or his relationships. Another theme could be the discovery of inner strength. Losing his sight might force him to dig deeper and find strength he didn't know he had. Also, friendship is often a theme, as his friends would play important roles in helping him through this difficult time.