Accessibility (visual and all the different impairments)

Greeetings,
I work as a tester, mostly for major banks, and I am great at it.

Question: How do I start learning about testing accessibility?
I'm 100% physically abled, but I want to learn how to check that i.e. the internet banking is accessible to a blind person.

I do not have anyone in my circle who is visually impaired / blind, so I do not have anyone to ask, but learning about the issues and then doing my best to alleviate them is what feels right for me.