What impact did the light bulb have on the world?

It killed the whale oil lamp and gas lighting industries. It created massive levels of light pollution, making it nearly impossible to see stars at night from populated areas.
You could say it caused us all to get less sleep.

Prior to the light bulb candles were used and for the most part everyones day was dictated by the sun.
The average amount of sleep a person got in those days was 10 to 12 hours a night compared to 6 now. Once the sun went down there just was not a whole lot to do, businesses had to shut down at dusk, travel was difficult and dangerous, and candles had a tendency to burn out over a short time so since the US was pretty spread out at the time you could not just walk to the corner store for another one.
Most of the major advances in technology came after the light bulb as a persons day could be extended as long as they could stay awake. Factories now could continue to manufacture goods inside buildings for extended periods or in shifts to meet demand.