Visual Impairments

I've been meeting a number of people recently who have visual impairments, and I've realized that while I have my blog tailored toward my own visual problems (large font, high contrast between text and background), I haven't even taken into account the possibility of someone who is fully blind coming on here and looking at my posts, which tend to include a large number of photos. I am familiar with the idea of putting captions underneath pictures describing the content, but I don't know how functional that is on Blogger.

Are there any people with visual impairments coming over here to read the random things that sprout from my brain? If so, what would be the most helpful thing for me to do to improve my blog in the interest of making it as accessible to as many people as I can?

** I'm not leaving out people with auditory impairments. I intend on adding closed captions to the videos I've put up so far. I've just been too busy with family weddings and medical stuff to finish it yet. Sorry!