Riddles: 3 light bulbs (Question)

There are two rooms.

In the first room are three switches. Each of the switches operates a light bulb in the second room. The second room has no windows, so it is not possible to look inside the room from outside.

The switches can be turned on and off as many times as one like. Moreover, one visit to the second room is allowed. How is it possible to determine which switch belongs to which light bulb?