I find there to be a lack of fanfiction that includes disabilities.

Basics

A fanfic where the OC or main character is blind, deaf, or mute and has to overcome/work around their disability. I am not perfect, but have done some research. Please let me know if there is anything outrageously false.

For a blind character, try including the difficulties they face as a sightless individual in whatever era of naruto you put them in. The character doesn't have to start out blind either. They could gradually go blind as they age (please look at characters other than Uchihas. Regular people go blind too), lose one or both of their eyes kakashi-style, or even be born without eyes at all (anophthalmia)

If it's the warring clan era, and unless the character is a sensor, they most likely would be a civilian. We are looking at war-time education, and with everyone having tight security over "clan secrets" information would be hard to come by. Having a character who wants to be a shinobi, but is unable to because of their disability is a great way to explore other fiction avenues. The character could, for example, instead focus on becoming an important political figure or strategist. More modern eras like the 3rd shinobi war and afterwards could lead to shinobi pathways for your character, especially if they are a part of a clan and can be taught chakra control early-on. The chakra bullshit can solve a lot of difficulties depending on how you want to play it out.

For a deaf character, working around the disability is both simple and complicated. Sign Language is a great alternate way of communicating, but it's unrealistic to expect everyone in a village to understand it. Complications can emerge in high-pressure situations where the OC was unable to communicate because someone else was not well-versed in sign.

Similar to blind characters, deaf characters don't have to be born deaf. They could slowly lose their hearing (war zones and explosions), become deaf in only one ear, or even be tortured where loss of sound was a result. There are many paths deafness can lead to.

In a civilian sense, sign could both alienate and strengthen the bonds between the OC and the rest of the community. Social status also has a great affect as higher class parents could have a difficult and negative relationship with the character, especially if they are in political social circles where arranged marriages are common. Lower class individuals might have a tougher relation with the OC, more so if a village is not very accommodating for disabled civilians. This is all with the assumption that hearing aids are non-existent. If they exist in your Naruto world, a tech-savvy OC could follow a path where they create/improve hearing aids.

It would be expected that if a deaf character goes the shinobi route, they won't reach very high up the ladder unless the writer has an ingenious way of working around the lack of hearing. Shinobi are highly dependent on their ears and not being able to tell if you broke a twig or not when trying to sneak up on someone is a sure way to end up dead.

For a mute character, first decide if they are selectively mute or if they are mute because of circumstance. And then stick with your idea. There is something infuriating about reading about a selectively mute OC who, out of nowhere, starts speaking in full sentences. If someone hasn't spoken in years, and then they suddenly just start, they will have difficulty speaking.

Selectively mute OCs usually have a reason why, but not always. Your OC could be exceptionally shy/anxious and only communicate within the household, be traumatized and thus became mute, or simply doesn't like talking. They might even be embarrassed by the sound of their own voice, especially if they're an SI who changed genders. Selective mutism is a different way to introduce a tragic background or highlight the difficulty SIs have when torn from their world and put into the Naruto-verse.

For circumstance mutism, having a character's vocal chords slit or tongue cut off could result in not being able to speak. An OC could be born with mutism as a result of other factors.

For a character going the shinobi route, there are a multitude of ways they could become mute. From torture to jutsu accident to everyday sparring, anything could happen. I personally would see mutism occurring after the character has gained shinobi status, with the likelihood of accident/torture-related mutism happening least in career chunin. Genin are more prone to accidents, and Jonin are more likely to be captured and tortured for information.

I would assume OCs who are mute would learn Sign Language as well.

Last minute notes:

You might also want to focus on the affect gender roles have on interpersonal relations and the impact of those societal expectations in relation to the time period. Economic pressures should also be a key point to remember as it is more difficult for those with disabilities to get a job.

Most of your readers are not trained medical professionals, so take a chance and explore. Do research before making claims, and take note of reviews when someone makes a correction. Fact-check their words, and improve your writing along the way. The most important thing you want to do is educate yourself so your writing doesn't present false information.

Nothing on here was meant to offend anyone in any way. I included this chapter because so many fan fictions ignore the possibility of there being characters who are disabled (outside of Lee and when Naru+Sasu lost their arms). I'm 90% sure the clans participate/d in inbreeding, but no one really comments on it. So many hide behind the magic of chakra to explain everything so I'd love to read more fics where people embrace differently-abled individuals.