For UV protection – that is, protection from short-wave light in the invisible spectrum – we must rely on manufacturer specifications and industry standards such as the UV400 label.
But when it comes to blue light protection, it’s always about visible light. The scientific term for this is HEVL, the abbreviation for high energy visible light. Since this light is visible, we can always examine any blue light protection promises with our own eyes. If blue looks unchanged through glasses, blue light also reaches the eye. It’s as simple as that.