I would recommend trying to study up on Section 508 compliance https://www.hhs.gov/web/section-508/index.html. It's a set of rules that all government orgs in the US must follow for making sure their content is accessible. If you do end up becoming visually impaired you'll end up with a unique perspective on building accessible websites.
Are there consulting firms that specialize in 508 audits? Seems like a potentially lucrative field given the activist lawsuits that happen in this area.
Yes, there have been professionals offering all types of services for 508 ever since it came out. Might be wrong, but none of the companies I have seen offering these services seems notably successful as a result of their 508 services. Compliance based services are rarely a money maker, though in some situations given predictable need and clients, compliance based services are frequently a way to build relationships that lead to more lucrative deals.
The W3C's Web Content Accessibility Guidelines (WCAG) are the basis for many accessibility laws and more useful for actually learning what makes a site accessible.
If you don't already place an emphasis on using semantic HTML markup, learn more about that, it's the foundation of accessible design.
Sighted developers should use a screen reader on their own sites to get an idea of what's up. Very simple changes with semantic HTML can make a world of difference. It's sometimes as simple as swapping tags for their semantic counterparts.
Yea my first programming job was translating word docs to accessible html for universities. The jobs around section 508 compliance seem mainly government related
