MONTREAL -- Universite de Montreal's (U de M) School of Optometry is warning the public about eye health problems caused by prolonged use of screens, which is more and more common during the COVID-19 pandemic.

Director of the School of Optometry Langis Michaud said that the increase in time spent in front of screens of all kinds risks impairing the quality of vision, including among students using distanced learning options for school.

Michaud, who has a doctorate in optometry, noted the recent rise in computer vision syndrome (SVO), which includes all of the vision problems associated with the use of a screen over prolonged periods.

He acknowledges that there is not an abundance of serious studies on this subject, but in December he produced an article based on a survey of 10,000 people that put the syndrome's prevalence at nearly 65 per cent ​​of the population working on screen.

Michaud said it's irresponsible to impose three-hour lessons on-screen with a 15-minute break. For eye health, it would be much better, in his opinion, to take short breaks every half an hour to let the eyes rest.

The U de M Optometry Clinic, which is open at 75 per cent of its capacity by virtue of its essential service status, is seeing more and more cases of early myopia resulting in particular from overuse of screens. Among this clientele are children barely 8 or 9 years old.

Michaud is reminding the public that high myopia is a risk factor for conditions causing blindness.

Cell phone screens force the gaze to be focused on a very close object, amplifying misalignment of binocular vision when it is brought 18 centimetres from the eyes.

Electronic tablets pose similar problems, but less acute, because it is used approximately 25 centimetres from the eyes. In the latter case, the lighting is more problematic, just like for the computer, which is even further away, 33 to 40 centimetres.

Michaud's note indicates that staring at a luminous surface for a long time increases the risks, especially if the ambient light is attenuated. He suggests avoiding looking at a screen in the dark at all costs.

-- this report by The Canadian Press was first published Feb. 4, 2021.