Pocalo doesn’t have electric lighting (or electric anything, for that matter).
Their interior lights are instead made of tiny ecosystems of bioluminescent fungi. The fungi have been domesticated to produce a brighter, whiter light than their wild counterparts.
The fungi survive by eating their own dead cells, so a well-balanced light can shine indefinitely. In practice, most lights don’t last forever: the glass gets cracked and throws the ecosystem off balance; the fungi reproduce too quickly (sometimes overgrowing to the point of bursting the glass); or they reproduce too slowly and die off. But a light made with a high level of craftsmanship may well last for hundreds of years.
There is no way to turn a particular light “on” or “off” (the fungi are either alive and glowing or dead and dark). In rooms where one wishes to achieve periodic darkness, like a bedroom, the lights will have some kind of hood which can be opened and closed.
A popular style of dimmable light is colloquially called an “eyelight,” as it has two adjustable lids which can allow for modulating both the intensity and the direction of the glow.