In-floor windows

I'm building a small two-story dome to start, with the top dome used as a loft / office / relaxation area.  I'm planning lots of small-to-medium windows in the upper dome.  I'd like to pass some of that light below.  What I'm thinking is putting circular windows near the edge of the dome, where people are unlikely to walk, and glazing them with tempered glass microwave trays.  The ones that sit on a roller and spin in the middle of the microwave.  

I've tested these trays by jumping on them and striking them with a mallet.  It did shatter when I threw a bullet-shaped, fist-sized chunk of solid iron through it.  But in general it was far more resilient than I expected. It didn't shatter into little squares as I expected, but rather largish chunks.  So it would not be safe to step through if it broke.

Does it seem foolhardy to put these windows near the edges of the dole to let some light through? Or is the minimal risk acceptable for the gain of extra light below?

The only person who I have known who did this had an old farmhouse where there was a hand dug well. He enclosed a porch over the hand dug well, but to make it unique, put a light down below so people could see down into the well, then put plexiglass over it. I think he used several layers.

Any glass place can get the plexiglass you need. They use it all the time for heavy equipment, particularly forestry equipment that needs ingrity if it gets hit by a limb or something.

I think windows at the top of the first story wall, where the wall meets the ceiling , would work better, and look better.

You can jump on the microwave carousel plate without it breaking, is that with it suspended or with it flat to the ground?

I remember sidewalk "windows" in New York City from when I was a child. They were usually near the access port doors, in the sidewalk, used to load things into the basement. They were some sort of glass brick, about 4 inches square. I'm not sure how they were supported but folks would walk on them without a care. So it is possible.

As a sidenote I also remember wooden escalators, they still show up in my bad dreams sometimes. Scary stuff.