Hello, my name is Joyce Attah from Kenya. I am working in a Designer Company. I am looking for the eye glasses. The definition of a blue-blocking lens is some extent of blue light is filtered out. There are two main things to consider; one is a range of filtering and another is the transmission. The range indicates the real wavelengths of filtered light and the transmission denotes how much of a specific wavelength band is filtered. Blue Block Lens not only protects our eyes from blue light but also from all the symptoms that go along with it.