Blue coated lenses are special coatings developed for the people who are constantly exposed to blue-violet light from digital devices such as tablets, computer screens, TV as well as mobile phones. It works by reflecting the emitted “blue light hazard” range of 400-500nm[1] from the source, preventing it from entering the eye.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5854379/