Exposure to blue light, like that from smartphones or tablets, may lead to early puberty in male rats, according to research presented at the 61st Annual European Society for Paediatric Endocrinology Meeting in The Hague. This study is the first to investigate the association between blue light exposure and early puberty in male rats, and sheds light on how environmental factors, such as screen time, impact early puberty and testicular tissue, which could eventually lead to future prevention strategies for children.