I can tell you what we plan on doing: After the time change at the end of october, we will have a light on for them for 5 am until 8 pm. They need 12-14 hours of light to continue to be good layers. So, we are going with a light to keep the eggs coming. We go through too many to have them stop.
Hey DonnaIL, you might try picking up a timer at a hardware store. I don't think they cost much, at most $20, and then you could have the light timed to go off at night and on again in the morning. I think having the light on all the time might stress the chickens out, or wear them down. Plus, you'll save on the cost of electricity if you have a timer.
Originally when the girls were small I left a light on 24/7. Later, I put a timer on so it would go on about 5am.and off at 8am. The timer died so I left the light off for awhile. I thought because it was summertime and the days were at their longest, no light wouldn't affect them, but their egg production did go down a little. I have a small light on again 24/7 and it doesn't seem to affect their laying habbits. They seem to lay better with the light on. I do have a red heat lamp i use in their coop in the winter. I had that on a timer to, so it would go on in the evenings and off in the mornings. They would be in their yard most of the time during the day.