Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easy for the eye to focus on. This means that when you're looking at computer screens and other digital devices, this unfocused visual "noise" reduces contrast and can contribute to digital eye strain.
Research has shown that lenses that block blue light with wavelengths less than 450 nm (blue-violet light) increase contrast significantly. This means your eyes aren’t straining to focus so hard and the chances of digital eye strain are reduced. Symptoms of digital eye strain include dry, sore eyes, discomfort and headaches.
Daytime Swannies help you focus on your computer screen with less eye strain, meaning you can focus more on your work, for longer periods.
In addition, research has also shown that blue light can help with memory and alertness, encourage serotonin production - all things that will help to boost your productivity during daylight hours.