All of these old selenium exposure meters remain responsive to light, some more than others. The heavy, bakelite-cased Weston at the top was one of the earliest to be made available to photographers in the 1930's. The General Electric DW58 on the left, nearly as old as me, seems as sensitive to light as when it was on the dealer's shelf. The feather-weight Sekonic L-158 on the right accompanies me on every photo outing.
None of the selenium meters I have used have been very good in low light, which is exactly when you need them most. Under normal daylight conditions they do ok, but my own guess work is usually pretty close to meter readings then. In fact, I often just take a single reading when I first step outside, and then go with my own estimates from that point onward. Given their somewhat limited range, the selenium meters might be better employed as a means for training your eye to gauge light conditions rather than as an immediate measurement tool. Still, I do feel a little more confident on photo outings with a light meter in my pocket.
For a really thorough treatment on the subject of light meters I highly recommend the web site about James Ollinger's Exposure Meter Collection. James does a great job of dealing with their history and use. The FAQ link is especially useful for new users of the old meters.