How do so many hours of screen time affect our eyes?
With the increase in the time spent using screens, it is normal for a person to encounter the well-known “visual fatigue” at the end of the day. This symptomatology is mainly caused by two factors:
- Blinking is considerably altered during the use of digital screens (which decreases from 6 blinks per minute, to two) with the consequent ocular dryness, which produces in the short term, burning sensation, foreign body and ocular inflammation.
- Accommodation spasm, which is produced by exercising the ciliary muscle that is responsible for focusing in the short-medium distance. When focusing for a long time at a short distance, this muscle can become “stiff” and cause blurred distance vision, headaches and sometimes even double vision.
Is high brightness or backlighting more harmful?
Having the screen brightness at maximum power, or intense natural light in the face, produces a more accentuated pupil closure (miosis), which, although it improves near vision in the short term, can produce headaches, photophobia and more marked visual fatigue in the medium term.
How can we reduce this impact?
There are many simple recommendations that we can carry out at home to avoid visual fatigue and the impact of so much time in front of screens:
- Work in well-lit environments, preferably with “natural light”. This light is better if it hits us indirectly so as not to induce problems in the medium term – backlighting is NOT recommended.
- Try to follow the 20/20/20 rule. Every 20 minutes, rest your eyes by looking for at least 20 seconds more than 20 feet (6 meters) away. This allows the ciliary muscle to rest and thus avoid spasms due to continuous effort.
- Longer rest (5-10 minutes) every 2 hours, we are at home…
- Avoid using contact lenses, these days it is better to use glasses.
- Use of artificial tears to avoid the sensation of dry eyes.
Are blue filter glasses really good for anything?
Protective screens and blue filter glasses (very widespread some time ago) have not been shown to be superior to placebo in several studies in terms of protection against ocular pathology or eye fatigue, as long as a series of visual hygiene rules that we have mentioned are followed. Therefore, it is not possible to generalize the recommendation of their use.