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.
If you don't already place an emphasis on using semantic HTML markup, learn more about that, it's the foundation of accessible design.