Blue light - ally or foe?

6 min

May 28, 2021

The natural and most important source of light is the sun, and our body takes advantage of the blue light it produces and adjusts to the amount by producing the appropriate hormone called the sleep hormone, melatonin, in the pineal gland.

What exactly is blue light?

Blue light, also known as high energy visible light (HEV), has the shortest wavelength of visible light and therefore produces the most energy.

The visible light that enters the eye and is perceived by humans falls within what is The visible light that enters the eye and is perceived by humans falls within what is known as the visible light spectrum and ranges from about 380 to 780 nm.
In it we can distinguish three basic fractions: red, green and blue.
The latter seems to play the most significant role in human physiology, as it regulates our circadian rhythm, and thus is responsible for the quality of sleep and well-being.

During the evening hours, when the light intensity decreases, the level of melatonin produced increases reaching its peak during the night hours from 24 to 3 in the morning.  This allows us to maintain a good night's sleep and consequently our well-being, and blue light plays a positive role in this case by regulating our diurnal rhythm.

Why are we actually afraid of blue light?

In recent years, the development of technology has unfortunately led to unnatural stimulation of our eyes and brain by artificially generated blue light emitted by monitor screens, tablets, smartphones or led bulbs.

It was noticed that the excess of blue light, instead of its positive role, began to initiate not only disorders in the production of melatonin and the associated serious disruption of sleep, but also lead to other ailments such as fatigue, headaches and eye problems.

Melatonin also has a very strong antioxidant effect, which means that it neutralizes the action of free radicals (abnormal combinations of oxygen), which prevents them from damaging proteins, lipids, and nucleic acids in our body. Its deficiency can therefore lead to diseases within the cells of the optic nerve and the macula.

Computer Vision Syndrome

In ophthalmology, the term "computer vision syndrome" has even been introduced, i.e. eye disorders in people working at a computer related to a disorder of tear film production and leading to dry eye syndrome in combination with head, neck and shoulder pain. Patients who visit an ophthalmologist complain in such cases of tiredness and redness of the eyes, sand under the eyelids, worsening of vision, intolerance of contact lenses or blurred vision.

It is also worth mentioning that, unfortunately, the above-mentioned problems concern not only adults, because we live in the times when school-age children also make intensive use of electronic devices (computers, tablets, smartphones, etc.), and the squinting of the eyes, because of which they often come to the ophthalmologist for a visit, in addition to the actual eye defect may often be due to a feeling of dryness caused by excessive use of devices emitting blue light.

Who is particularly vulnerable to the harmful effects of blue light?

Nowadays, electronic devices and the related emission of blue light dominate the whole world, so even though the disorder is temporary, it can affect almost anyone who regularly works at a computer and does not take proper preventive measures. This is the reason why during occupational medicine examinations, office workers are referred for an ophthalmological check-up, along with such professions as drivers, workers employed in industry or agriculture.


The best solution, apart from limiting the time of eye exposure to the harmful effects of blue light and proper hydration, turned out to be the additional prevention in the form of specially designed for this purpose glasses containing a natural pigment present in the skin, hair and eyes of mammals - melanin. Its strong antioxidant properties and ability to absorb and scatter ultraviolet radiation and blue light have found application, among others in ophthalmology.

Specially composed glasses (be it "zero-light" or prescription glasses), whose lenses contain the appropriate proportion of melanin effectively protect the eyes against the harmful effects of radiation, reduce the blurring effect and the risk of glaucoma, cataracts and macular degeneration, and at the same time allow to maintain the fullness and brightness of perceived colors.

It should be added that glasses with melanin content can have all necessary corrective functions, as well as be used by people who do not require vision correction solely for protective purposes.

Dr Agnieszka Siennicka, MD
Retina Outpatient Clinic and Ophthalmology Hospital

You might also be interested in these

New products, blog updates, deals, and more.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.