You're not the demo. So your no thanks is expected.
But, there are plenty of people with eye problems as OP laid out, and I can guarantee you that a large amount for them would be happy to pay $9.99 for the ability to actually consume and enjoy printed books that don't have pdf/eBook editions.
But saying “don’t do it” is so off-base. It’s completely dismissing an entire sector of the market and humanity that isn’t like you.
And perhaps that sort of comment, if given to a first time founder working on a tool that helped a swath of the population… they might see that and get discouraged.
And then that tool that could legitimately improve people’s days, by allowing them to engage in parts of life they can’t easily access by themselves, wouldn’t exist.
As someone who has spent my entire career in the realm of selling things, this is a solid business model that provides a great solution to a likely, very underserved, market.
Plus the tech is cool and sounds fun to build. So, good work OP!