When I was young, the lights didn't come on until the Gospel. The Lessons were all read in quite symbolic and appropriate darkness. The "Lumen Christi" was the light of our hundreds of candles lit from the Paschal Candle, not dozens of hundred watt bulbs in the ceiling.
Last year I think the lights come on as the Gloria is sung for the first time since Lent began..............and after the Gloria, the Epistle and then the Gospel are read. But maybe my memory fails me.