The solid grey is the paint on the back of the silvering. It sounds as if the glass was etched on the back side and then the silvering was applied. You could remove the silvering off the mirror, which is a nasty process. You strip the paint off the back of the mirror with stripper and then you remove the silvering with muriatic acid which is a very strong chemical with strong fumes. That would give you a clear piece of glass, with the detail intact if it is etched. If it is something that is painted on the back, you might end up removing that too and then you'd have a plain piece of glass after all your efforts. But if the detail remains you could mount this glass over new mirror like a sandwich to get a similar effect. It would be much easier for them to etch or sandblast this detail into a mirror from the front surface.

Let's assume you followed the guideline above. Let's say you're 66" tall; the bottom of the cabinet might be 62 - (26 / 2) = 49" above the floor and the top 75" above the floor. The ceiling is 96" tall so there would be 96 - 75 = 21" of vertical space between the top of the cabinet and the ceiling. My Tech Lighting Span vanity light is 6" deep. If you didn't place your vanity light too close to the top of the medicine cabinet and got a light at least this deep, I don't think you'd have any problem with shadows.

Hello, Does a recess mounted medicine cabinet with lighted mirror exist that has replaceable lights, should one go out? In the $500 price range? Thanks, Lisa

There isn't a generic solution for this. If you want useful input, you need to post a picture or two.