What kind of advice are you looking for?

How about adding a light in the hall? That would be cheaper than replacing all the doors.

I don't know if I'd want a transparent door on my bedroom. Have you thought about installing a solar tube (google "tubular skylight")? It's basically a small, round skylight with reflectors in it to maximize the natural light coming in. They're not too expensive, and are supposed to be easy to install. That's what I'm doing in my dark hallway.

The house has a double ceiling (lowerer by previous owners).
Can I find this tubular skylight at Lowe's? I'm looking for something to add more light in the hallway. It's near time for me to retire and don't have a lot of money to invest in anything too expensive. I'll go to Lowe's website and see what they have. If you have further suggestions please let me know. Thanks so much for responding.

The double ceiling shouldn't be a problem, because you can easily adjust the length of the tube. I'm not sure if they have tubular skylights at Lowes, but they're only a couple hundred dollars on the Web - there are a wide variety of sizes and brands. In the end, it would probably be cheaper than buying several glass-paned doors.