My son has been wearing the polarized babiators since he was 4 months old. He is turning 5 now and has outgrown the 3 to 5 years size so i was so happy to see they added polarized glasses for 6+. We love them! He never leaves the house without them. We have passed down our 0 to 3 years glasses which have been worn by 3 children now and they are still going strong. My nephew is looking forward to the 3 to 5 year glasses!