Has he already adjusted the system-wide font size? I would tend to expect so, but just in case not …
Start with the Settings app (the gray one with the gear wheels). Go to “Accessibility.” Then, to “Display & Text Size,” and next to “Larger Text.” With vision that restricted, he might need to turn on the option for “Larger Accessibility Sizes.”
If even the largest size with that option isn’t enough for him … then I would steer him in the direction of somebody in the blind community with expertise. Even if there’re more settings (etc.) to tweak, I would expect somebody in the community to have much better insight as to what is and isn’t likely to be effective. Indeed, I’d expect there to be something that wouldn’t even occur to most people that would be a better solution than most of what we’d all try.
Also note that there’re many other options in Settings to make iOS more usable to people with limited vision. I also wouldn’t be surprised if one of those does more to help your friend than just making everything bigger. Again, somebody within the community might be able to offer better guidance and insight.
Cheers,
b&
