As an optometrist myself, I found that interesting. I couldn't tell you exactly what that may have been used for though. Some sort of retinal camera would be a good guess. We have one diagnostic machine that is built around a Northwood Pentium 4 and runs Windows 2000. I use it almost every day!

The guy in the video mistakenly referred to an Inport mouse controller card as a PS/2 mouse. Microsoft Inport is a bus mouse.

Also, doesn't he need to load an EISA config file to properly run the graphics card?

I don't think I'd even heard of bus mice until about 3 years ago.

What was the advantage of it over a good old serial mouse?

I noticed that too. But TBH, I had always seen "Bus mouse" in like Win 3.x setup and assumed it was another name for PS/2 until just recently as well. I still would have no idea what to do with EISA. I've never seen it in the wild before.