Tammy Chalala, a retired dietitian in New York, was thrilled with the results of her cataract surgeries, which left her with close to 20/20 vision. She said she paid nearly $4,000 out-of-pocket for her two surgeries last year because she opted to have her doctor use a laser to assist with the procedure. Chalala, 69, chose that method over the traditional scalpel after doing research online and consulting with her doctors, believing it would give her the best outcome. “It seemed like the better option,” she said. Cataract surgery — one of the most common operations paid for by Medicare...