why does eric church always wear sunglasses

Eric Church always wears sunglasses on stage primarily to protect his eyes. He wears contact lenses, but the bright stage lights would "bake" his contacts and cause them to fall out, making him effectively blind on stage. Wearing sunglasses was suggested as a solution, and it worked to shield his eyes from the harsh lighting. Although it was never planned as a fashion statement, the sunglasses became his signature look. He typically only wears the sunglasses when performing because his eyes don't do well in the intense stage lights, and it doesn't feel right to perform without them.