Blue light emmissions from the modern world
Light is the product of electromagnetic particles travelling at various wavelengths. Theses waves emit energy- the shorter wavelengths are typically associated with higher energy values. The various wavelengths are linked to colour and grouped into the following categories :
Ultraviolet UV Rays
The human eye is sensitive particularly to what is known as the Visible Spectrum. This range lies between the colours blue/violet to red and every colour inbetween. We have all seen the affects of white light being split into its constituent parts in the form of a rainbow following sun after rainfall. The high energy area of this is the blue end of the rainbow.
Blue light is actually everywhere but typical sources of Blue Light are Fluorescent & LED strip lighting, TV's, Computers, Lap Tops, Smart phones. As Blue Light is a source of High Energy Visible (HEV) Light it has a behaviour known as 'flicker' and that property is more pronounced with blue light than with the longer wavelength light. Flicker has been shown to be an issue which will cause glare. Glare in turn affects visual contrast and thus clarity and crispness are affected detrimentally.
The natural filters within the visual system of the human eye are not sufficient to protect them from bright sunlight (which is why we wear sunglasses). Similarly the same filters are not efficient at dealing with blue light. Recent studies suggest such eye problems such as Cataract,Age Related Macula Degeneration and Retinal damage could be as a result of over exposue to Blue Light Sources. There is however a solution - ask in practice about incorporating a Blue Light Filter into your spectacle correction.