They're a 13 watt bulb that's equivalent to a 60 watt light bulb.

The shift from incoherence to coherence can bring dramatic effects: a 60-watt light bulb whose light waves could be made coherent as a laser, would have the power to bore a hole through the sun--from 90 million miles away.

A light bulb went off.

I just think a light bulb went on.

You don’t have to be the brightest bulb in the house; when the darkness comes, you will be 100 watt.

Going blonde is like buying yourself a light bulb!