How to prepare a presentation if there is a visually impaired person in the audience? When preparing a presentation, I usually avoid putting a lot of text and then read the slides. To me, the best presentation contains very good figures with presenter explaining them, and not reading what is already written. Thus, I prefer using little to no text and use only figures if possible.

While I was helping a group of collegues for their project presentation, they mentioned that there is a visually impaired student in the classroom. Although I encouraged them to present the topic using figures and drawings (the topic was very suitable for this), I wonder now whether it is the best practice.

Moreover, I realized that this might also be the case during a conference talk, for which we do not have the prior knowledge of the presence of a visually impaired person.

So, my question is for the ones who have visual disability, who know such people, or who had similar experience. What is the best way to prepare a presentation? What to think and what not to overthink?
From conversations with my wife, who is blind, you don't want to overthink this too much. Most of the things you can do to help the visually impaired will help everyone in the audience. 

For starters, I'd suggest sending out the slide deck beforehand if at all possible, since this helps everyone be prepared. You should also make sure any figures have some sort of caption or title on them with a brief description of what's being shown. This will help anyone using a screen-reader to follow along. 

The major thing that will help is making sure that you're giving general descriptions of the charts and figures, as well as the takeaway from those figures. This is good practice in general, since it ensures that your audience understands what you're trying to show with a figure and is invaluable to someone with low vision because it allows them to better understand the information being presented.

The true goal is to ensure that someone with only an audio recording of your presentation, no slides at all, can follow along to a reasonable extent. A couple of things may be missed, but the overall meaning should be apparent.