Spectacles co-developed by PolyU and Hoya Vision have proved effective in slowing down myopia progression by half even in the extreme circumstances of COVID-19 lockdowns.

The finding came as another PolyU study showed that the share of students with astigmatism has increased almost by half during the pandemic.

The impact of stay-at-home learning to schoolchildren’s vision health has attracted renewed attention as face-to-face classes are suspended once again during this new wave of the novel coronavirus epidemic in Hong Kong.

“The changes in teaching and learning under the pandemic have led to an increase in the time spent on electronic devices and near-vision work activities for children while less time is spent outdoors, aggravating the risk of myopia progression,” said Dr Henry Chan, Associate Professor of PolyU’s School of Optometry.

Dr Chan and his research team analysed 171 Hong Kong schoolchildren aged 7 to 13 in 2019 and during school suspensions in 2020. They found that even with more rapid myopia progression during the pandemic lockdown measures, the PolyU-innovated Defocus Incorporated Multiple Segments (DIMS) Spectacle Lens (co-developed with Hoya Vision) was associated with a 46 per cent lower degree of myopia progression in comparison with a conventional single vision lens (SVL).

Furthermore, in the student group that spent more time in lockdown, the advantage of the DIMS lens was more prominent and slowed down myopia progression by 52 per cent.

But the lockdown challenges are not limited to myopia.

In a pioneering study about how the pandemic may affect schoolchildren, another PolyU research team led by Dr Kee Chea-su, Associate Professor of the School of Optometry, found that there was a significant increase in astigmatism among kids – contradicting pre-pandemic studies that showed astigmatism normally drops during childhood.

The team compared the vision screening results of students aged 8 to 10 years old in a local primary school. The share of children with astigmatism in 2020 was 49.1 per cent, compared to 33.9 per cent in 2018. Among the children who participated in both the 2018 and 2020 studies, the share of those with astigmatism doubled, from 34.2 per cent to 73.7 per cent.

Dr Jeffrey Leung, Research Assistant Professor of the School and a member of the team, said, “Our survey also found that schoolchildren spent on average 30 to 60 minutes longer a day on digital screens like smartphones and tablets in their leisure time.”

The two PolyU research studies were published in the international academic journals JAMA Network Open and Clinical and Experimental Optometry respectively in January 2022.