If you use the small votive candles in those, like others suggest I would put them in small glass votive holders. You won't really see them when in use because the pattern of the glass will hide them and they will protect the outside glass. If you lightly spray the inside of the votive holder before putting the votive in, it will make the melted candle easier to remove later. You can also soak the votive holder in hot water to loosen the candle when it is time to change it.
The new LED lights are cool to, some even have the flickering effect.