One of my motivations for buying a new Bible for my husband was that he found it near to impossible to read the one that he had. He had a large print Bible but it wasn't large enough, and he definitely needed a jumbo size print Bible.
For anyone with bad eyesight, I would recommend a jumbo, or giant print Bible. This print will be easy on the eyes and help to prevent eye strain. The large print is nice and big for someone who may have less than perfect eyesight but who can still see pretty well.
The regular print is okay for someone who can read other regular print books and most Internet pages. The advantage of regular print is that it allows for a smaller Bible, or allows for more room for study helps and commentary. For those without visual impairment, the larger print can seem annoying. I myself prefer a regular print over a jumbo or large print. I simply prefer the look of the page better.
There are still books printed in small print, as well. This feature is great for being able to create a small, portable Bible, and allows the printers to fit a lot of content, including study helps, within the pages of the Bible.
Another feature to check for is to have the words of Christ in red. This is a personal preference. Some prefer it but others find it distracting. Be sure to check out which one your Bible has.