For a few years it has been recommended to wear glasses with blue filters on the lenses while working with digital screens. Blue light glasses work thanks to an internal filter that has nothing to do with the color of the glass or the anti-reflective coating. This blue filter can be added to both prescription lenses and conventional sunglasses, including photochromic ones.
What is blue light?
Blue light is present in visible light. It is predominant in the light that the sun emits at noon, when the sky is clear, and also in that emitted by the screens of digital devices. Blue light is not only a light source that we identify with the color blue, which is perceived when the wavelength of visible radiation ranges between 400 and 495 nm, which implies that it is quite energetic. Blue light or bluish light is also called lighting with a high component of this type of visible radiation in particular, as is the case of the light emitted by a computer, television or a digital book reader.
Benefits of wearing blue filter lenses
It has been proven that exposure to blue light from certain hours in the afternoon or at night interferes with circadian rhythms, causing insomnia problems among other imbalances. There is also a debate about whether prolonged exposure to this type of light decreases the age of onset of age-related macular degeneration (AMD), without convincing statements being made at the moment because the clinical study requires several years of patient follow-up.
What is clear is that anti blue light glasses work by filtering light with the wavelength values that correspond to this color of the visible spectrum, so blue filter lenses offer the benefits of avoiding prolonged exposure or hours to this type of visible radiation. First of all, they prevent the alteration of the sleep-wake cycle and, in the event that this type of lighting damages the retina, the use of lenses with a filter for blue light would also be the way to prevent damage.
How do I know if my glasses have a blue filter?
It is not easy to know if a pair of glasses contains a blue filter or not because there are several hoaxes about it. The blue lenses of eyeglasses do not protect against blue light, nor do the bluish anti-reflective ones, despite the fact that sometimes you can see through them with shades similar to those offered by true anti-blue light lenses.
There are two ways you can check whether or not your glasses have a blue light filter:
On-site test
If you place the glasses on a piece of white paper and shine a bluish LED light through the lenses, you should see how when the light beam passes through the glass it hits the paper very dimly, in contrast to the way it looks. the paper when light falls directly on it and not through the lens.
Certificate
Some manufacturers offer a Certificate of Authenticity issued by an independent company, which provides security when you buy glasses or contact lenses online, but you should be aware that not all manufacturers include this certificate in their perfectly valid anti-blue light lenses.
Blue light filters can be added to prescription and non-prescription glasses, as well as sunglasses, but you should not confuse this filter with anti-reflective. A blue anti-reflective does not give you the benefits of a blue light filter lens, although it may give you a similar visual sensation.