Effects of ultraviolet light on the eyes

Ultraviolet light is the name given to electromagnetic waves, whose wavelength is between the visible range and X-rays, that is, between approximately 420 and 100nm. This radiation is responsible for the annoying burns on the skin, which occur after prolonged exposure to the sun at critical times. Also, our eyes can suffer irreversible damage if we do not take the care.


Ultraviolet radiation is divided into three types, depending on its wavelength and the role it plays in human health:

- UV-C radiation (100 nm to 290 nm) the ozone layer prevents it from reaching the earth.

- UV-B radiation (290nm to 320nm), the most damaging and main responsible for damage to the eye, skin and immune system (decreases the cellular immune response at the irradiated site and at higher doses decreases systemic immunity).

- UV-A radiation (320nm to 400nm) is less harmful, responsible for tanning and photosensitivity reactions.

Protection of the eye from UV radiation

Most of the UV radiation is absorbed by the cornea and the lens, while less than 1% reaches the retina. Constant and prolonged exposure to sunlight can lead to various eye pathologies, due to its cumulative effect.

Treble (may be reversible):

- Erythema (redness).
- Keratoconjunctivitis (UV-B radiation snow, UV-C radiation arc).
- Herpetic infections, due to decreased defenses.
- Burning of photoreceptors in the foveal retina (irreversible). It occurs when looking at an unprotected solar eclipse.

Chronic (for cumulative damage, it is irreversible):

- Photo aging of eyelid skin and skin cancer.
- Pinguecula (conjunctival thickening), pterygium (thickening and proliferation of the conjunctiva towards the cornea) that, without being malignant, are unsightly.
- Conjunctival squamous cell cancer.
- Herpetic disease due to immune depression.
- Especially cortical cataract.
- Age-related macular degeneration (irreversible macular damage, which produces a decrease in central visual acuity, which is what allows us to discriminate details, read).

We can find many ways to protect our eyes from UV radiation

Every day there are more resources available to protect our eyes from UV radiation. First of all, we must not forget that radiation affects our visual health throughout the year and not only throughout the summer season.

An excellent option to protect our eyes from radiation is through the use of screens or UV filters incorporated into optical lenses and sunglasses (properly sized and shaped). This, since with UV filter 100% protection is achieved. The use of a visor or a clip on sunglasses also helps.

It is important to remember that we should all use UV protection outdoors, whether it is winter or summer, whether it is clear or cloudy, and from childhood: the more years of exposure to UV light, the greater the probability of developing some type of damage, either cutaneous and / or visual.

One thing is certain, taking preventative measures against excessive sun exposure can prevent us from unwanted risks. Hopefully this article can increase our awareness of the dangers of excessive sunlight. Thank you for reading!