FLUKE Frets

I love my fluke. It is probably my favorite uke, but I find I have a bit of trouble seeing the frets unless the room is very well lighted.

Has anyone solved the issue of how to see the frets on the polycarbonate fretboard. If so, how? (Yes, I know, bright lights).

I frequently switch from my soprano uke, to the concert scaled fluke, and then the tenor...so my feel for the fretboard might not be as sharp as it would be if I stayed with only one length.

Idea please. Thanks in advance.

http://www.inlaystickers.com/servlet/the-Fret-Markers/Categories
http://www.inlaystickers.com/servlet/the-Ukulele/Categories

Some have marked their frets with silver sharpie. others have used fingernail polish to make side dots...