I went to a Craft and Quilt Show aq week ago with SWMBO a woman on one stall had these finger lights in fact one switched on her finger. Yes I loved them so I bought six.
Reason I wanted to show Bill they can be bought for very little on the net Google finger light mate.
I gave up trying to hand hold the camera, fingered light and pen so best I could do, using this for very fine work or sight deprived writing magnificent IMHO.
There is even a U Tube video on how to change batteries at the buying price why bother my thought.
Peter.