Search
What are you looking for?
Start main content

Press Releases

Press Releases

https://www.med.cuhk.edu.hk/press-releases/cuhk-study-demonstrates-a-2-5-fold-increase-in-myopia-incidence-in-children-during-covid-19-pandemic-due-to-less-time-outdoors-and-more-time-on-screens
https://www.med.cuhk.edu.hk/press-releases/cuhk-study-demonstrates-a-2-5-fold-increase-in-myopia-incidence-in-children-during-covid-19-pandemic-due-to-less-time-outdoors-and-more-time-on-screens

CUHK Study Demonstrates a 2.5-fold Increase in Myopia Incidence in Children During COVID-19 Pandemic Due to Less Time Outdoors and More Time on Screens

COVID-19 study on myopia

A study by CU Medicine found a 2.5-fold increase in myopia incidence among schoolchildren in Hong Kong during the COVID-19 pandemic, triggering a “myopia boom”.

 

(From left) Professor Calvin C.P. PANG, S. H. Ho Research Professor of Visual Sciences, CUHK; Professor Clement C.Y. THAM, S.H. Ho Professor of Ophthalmology and Visual Sciences, CUHK and Chairman of the Department of Ophthalmology and Visual Sciences; Dr. Jason C.S. YAM, Associate Professor; and Ms. Mandy NG, Nursing Officer, Department of Ophthalmology and Visual Sciences, CU Medicine.

Many countries and cities across the world implemented school closure or social distancing measures in response to the COVID-19 pandemic, including Hong Kong. A recent study by The Faculty of Medicine at The Chinese University of Hong Kong (CU Medicine) showed that this unprecedented level of quarantine, prohibiting outdoor activities and restricting daily routines to indoor activities, has triggered a “myopia boom” in school children in Hong Kong.

 

The Department of Ophthalmology and Visual Sciences conducted a prospective population-based study to evaluate the impact of the COVID-19 pandemic on myopia incidence and progression among school-aged children in Hong Kong and found a 2.5-fold increase in myopia incidence. The findings have been published in the international journal British Journal of Ophthalmology.

 

Hong Kong is among cities with the highest prevalence of myopia worldwide

 

Myopia is the most common ocular disease worldwide and is responsible for multiple ocular complications which carry a high risk of irreversible vision loss later in life due to excessive eyeball growth in myopia. It is predicted that approximately half of the world’s population will become myopic by 2050, with the highest prevalence in East Asia. Hong Kong is among cities with the highest prevalence of myopia in the world, affecting more than 40% of school children at the age of eight.

 

Professor Clement C.Y. THAM, S. H. Ho Professor of Ophthalmology and Visual Sciences, CUHK and Chairman of the Department of Ophthalmology and Visual Sciences, CU Medicine remarked, “The concern over a myopia boom in children during COVID-19 hits particularly close to home, as Hong Kong is one of the world’s most densely populated cities, with the overwhelming majority of the population living in urban areas, where outdoor spaces are hard to come by. Under these circumstances, school children are spending significantly less time outdoors and more time on near work. These two behaviours are associated with myopia development and progression.”

 

Professor Calvin C.P. PANG, S. H. Ho Research Professor of Visual Sciences, CUHK and Director of the Shantou University / The Chinese University of Hong Kong Joint Shantou International Eye Centre explained, “High myopia (-6.00 diopters or above) can lead to sight-threatening complications, including glaucoma, macular degeneration, retinal detachment and cataract. Wearing glasses or having laser refractive surgery can help improve vision, but cannot resolve the eyeball elongation problem or reduce the risk of complications, therefore prevention should be given top priority.”

 

Dr. Jason Yam

Dr. Jason Yam, principal investigator of the study says less outdoor time and more screen time are the major reasons of the myopia boom during the pandemic.

Nicole

Nicole’s myopia progressed from -4.0D to -5.25D during the pandemic (from January to August last year). She said the increase in screen time for online lessons made her eyes feel uncomfortable and she sometimes has dry eyes.

School children on average spend 7 hours on screens but only 24 minutes outdoor per day during the pandemic

 

Research team recruited 709 children (COVID-19 cohort) between December 2019 and January 2020 when school closures and restrictions on social activities were in place due to COVID-19, and followed their myopia progression for at least eight months until August 2020. The control group (pre-COVID-19 cohort) consisted of 1,084 children that had been followed up for three years before the major COVID-19 outbreak in Hong Kong in January 2020. The team carried out eye examinations for the children and asked about the amount of time they spent outdoors, on screens and doing near work.

 

The results showed a 2.5-fold increase in myopia incidence in children during the pandemic and the progression speeded up.

 

 

COVID-19 cohort

Pre-COVID-19 cohort

Estimated annual incidence of myopia

30%

12%

Estimated annual myopia progression

-0.80D

-0.41D

Estimated annual axial elongation

0.45 mm

0.28 mm

The research also demonstrated a change in lifestyle for the school children.  

 

 

COVID-19 cohort

Pre-COVID-19 cohort

Time spent on outdoor activities

24 minutes per day on average

75 minutes per day on average

Time spent on screens indoors

7 hours per day on average

2.5 hours per day on average

Nicole

CU Medicine team suggests schoolchildren should develop healthy habits for using digital devices, like taking a 30-second rest after looking at the screen for 30 minutes. And they are recommended to increase outdoor time to 2 hours per day or 14 hours per week. 

Dr. Jason C.S. YAM, principal investigator of the study and Associate Professor from the Department of Ophthalmology and Visual Sciences, CU Medicine remarked, “Our study showed more school children became myopic during the pandemic due to less time outdoors and more time on screens. Schoolchildren are recommended to increase outdoor time to 2 hours per day or 14 hours per week. Outdoor play is good for the eyes because sun exposure helps to increase Dopamine release and slow down eye growth. Secondly, the increasing reliance on digital devices needs to be addressed. As more educational activities are online, electronic devices are used more frequently for reading and writing, consequently there is much more near work for children. Educators and parents should help children develop healthy habits for using digital devices. Thirdly, considering such lifestyle shifts that affect vision, effective myopia control through pharmacological or optical interventions should be implemented to inhibit myopia progression in children at high-risk.”

More Press Releases

CUHK Study First Proves Low-Concentration Atropine Eye Drops Reduce Myopia Progression in Children with Minimal Side Effects

CUHK Study First Proves Low-Concentration Atropine Eye Drops Reduce Myopia Progression in Children with Minimal Side Effects

Research
CUHK Launches Vision Screening for Hong Kong Children

CUHK Launches Vision Screening for Hong Kong Children

Clinical service
CUHK Establishes Lam Kin Chung . Jet King-Shing Ho Glaucoma Treatment and Research Centre  To Promote Advancement in Glaucoma Management in Hong Kong through Research and Training

CUHK Establishes Lam Kin Chung . Jet King-Shing Ho Glaucoma Treatment and Research Centre To Promote Advancement in Glaucoma Management in Hong Kong through Research and Training

Donation
CU Medicine Survey Shows Only 25% of Unvaccinated People Intend to Get Inoculated in the Coming Six Months “Multiple Incentives” are Urgently Needed

CU Medicine Survey Shows Only 25% of Unvaccinated People Intend to Get Inoculated in the Coming Six Months “Multiple Incentives” are Urgently Needed

Research
CU Medicine Estimates 20,000 COVID-19 Hidden Infections in Hong Kong  All Vaccinated Persons in HK Developed Neutralising Antibody After Two Doses  Urgent Call for the Largely Unprotected Population to Get Vaccinated

CU Medicine Estimates 20,000 COVID-19 Hidden Infections in Hong Kong All Vaccinated Persons in HK Developed Neutralising Antibody After Two Doses Urgent Call for the Largely Unprotected Population to Get Vaccinated

Research
A Global Study Led by CU Medicine and HKUMed Discovers  a Hepatitis C Virus Drug as Potent Treatment for COVID-19

A Global Study Led by CU Medicine and HKUMed Discovers a Hepatitis C Virus Drug as Potent Treatment for COVID-19

Research
CU Medicine Study Shows Recovered Mothers Transfer COVID-19 Antibodies to Newborn Babies

CU Medicine Study Shows Recovered Mothers Transfer COVID-19 Antibodies to Newborn Babies

Research
CU Medicine Study Suggests Toddlers are at High Risk of Being  “Silent Spreaders of SARS-CoV2 Infection”

CU Medicine Study Suggests Toddlers are at High Risk of Being “Silent Spreaders of SARS-CoV2 Infection”

Research
CU Medicine Study Shows Modulation of Gut Microbiota  Helps Enhance Safety and Efficacy of COVID-19 Vaccine

CU Medicine Study Shows Modulation of Gut Microbiota Helps Enhance Safety and Efficacy of COVID-19 Vaccine

Research
CU Medicine and International Surgeons Suggest Patients with Positive COVID-19 Results Should Delay Surgery for Seven Weeks to Reduce Death Risk

CU Medicine and International Surgeons Suggest Patients with Positive COVID-19 Results Should Delay Surgery for Seven Weeks to Reduce Death Risk

International collaboration
CU Medicine Finds New Evidence for Link between Gut Microbiome and COVID-19 Severity Microbiome Imbalance Might Influence “Long COVID” Risk

CU Medicine Finds New Evidence for Link between Gut Microbiome and COVID-19 Severity Microbiome Imbalance Might Influence “Long COVID” Risk

Research
CU Medicine Survey Shows Government Recommendation as the Strongest Driver for COVID-19 Vaccine Acceptance

CU Medicine Survey Shows Government Recommendation as the Strongest Driver for COVID-19 Vaccine Acceptance

Research
CUHK Introduces Nasal Strip Sampling for COVID-19 Test As a Superior Tool for Surveillance in a Wide Age-Range Population

CUHK Introduces Nasal Strip Sampling for COVID-19 Test As a Superior Tool for Surveillance in a Wide Age-Range Population

Research
40% of Hong Kong People Show Gut Dysbiosis Comparable to that of COVID-19 Patients CUHK Microbiome Immunity Formula Hastens Recovery of COVID-19 Patients and Offers Hope to Boost Immunity

40% of Hong Kong People Show Gut Dysbiosis Comparable to that of COVID-19 Patients CUHK Microbiome Immunity Formula Hastens Recovery of COVID-19 Patients and Offers Hope to Boost Immunity

Research
CUHK Study Shows Exposure Settings Impact COVID-19 Transmission With Entertainment Setting Showing Propensity for Widespread Dispersion

CUHK Study Shows Exposure Settings Impact COVID-19 Transmission With Entertainment Setting Showing Propensity for Widespread Dispersion

Research
CU Medicine Found SARS-CoV2 in Infants' Stool A Coronavirus Testing Centre Is Established for Paediatric Population to Identify Silent Carriers

CU Medicine Found SARS-CoV2 in Infants' Stool A Coronavirus Testing Centre Is Established for Paediatric Population to Identify Silent Carriers

Research
Most Deaths from COVID-19 in Hong Kong are of 60 Years Old or Above CUHK Initiated International Effort in Devising Strategies to Protect Older People with Dementia amid COVID-19 Pandemic

Most Deaths from COVID-19 in Hong Kong are of 60 Years Old or Above CUHK Initiated International Effort in Devising Strategies to Protect Older People with Dementia amid COVID-19 Pandemic

Research
CU Medicine Study Shows Liver Injury is Common and Prognostic in COVID-19 Patients

CU Medicine Study Shows Liver Injury is Common and Prognostic in COVID-19 Patients

Research
CUHK Researchers Uncover Diabetes as a Potential Risk Factor for COVID-19,  and Possible Mechanisms

CUHK Researchers Uncover Diabetes as a Potential Risk Factor for COVID-19, and Possible Mechanisms

Research
CU Medicine Survey Shows Global Urological Services have been Significantly Deferred due to COVID-19 Pandemic

CU Medicine Survey Shows Global Urological Services have been Significantly Deferred due to COVID-19 Pandemic

Research
CU Medicine Develops a Probiotic Formula to Target Imbalance in Gut Microbiota in COVID-19

CU Medicine Develops a Probiotic Formula to Target Imbalance in Gut Microbiota in COVID-19

Research
CU Medicine Recruits 3,000 Persons to Investigate Hidden Infection and Break the Obstacles in Containing COVID-19 in Hong Kong

CU Medicine Recruits 3,000 Persons to Investigate Hidden Infection and Break the Obstacles in Containing COVID-19 in Hong Kong

Research
CU Medicine Offers Free Stool Screening Test for COVID-19 in Children arriving at Airport

CU Medicine Offers Free Stool Screening Test for COVID-19 in Children arriving at Airport

Clinical service
CUHK Finds that the Coronavirus Can Persist in Stool after Its Clearance in Respiratory Tract Will Conduct Stool Test for People in Quarantine Camps for Early Identification

CUHK Finds that the Coronavirus Can Persist in Stool after Its Clearance in Respiratory Tract Will Conduct Stool Test for People in Quarantine Camps for Early Identification

Research
CU Medicine Announces the Community Response Study Results During the Early Phase of the COVID-19 Outbreak in Hong Kong

CU Medicine Announces the Community Response Study Results During the Early Phase of the COVID-19 Outbreak in Hong Kong

Research
CUHK Receives Nearly HKD 78 Million from HKJC to Launch Ophthalmic Programmes for Children’s Eye Care and Ophthalmic Microsurgical Training

CUHK Receives Nearly HKD 78 Million from HKJC to Launch Ophthalmic Programmes for Children’s Eye Care and Ophthalmic Microsurgical Training

Donation
CUHK Launches World’s First Study Utilizing Retinal Imaging for Alzheimer’s Disease Screening in Chinese Population

CUHK Launches World’s First Study Utilizing Retinal Imaging for Alzheimer’s Disease Screening in Chinese Population

Research
CUHK Pao So Kok Macular Disease Treatment and Research Centre Opens Study Sees Correlation between Protein Angiopoietin2 and Wet Age-related Macular Degeneration

CUHK Pao So Kok Macular Disease Treatment and Research Centre Opens Study Sees Correlation between Protein Angiopoietin2 and Wet Age-related Macular Degeneration

Donation
CUHK Research Reveals Use of Ortho-K Lens as a Major Risk Factor for Microbial Keratitis in School Children

CUHK Research Reveals Use of Ortho-K Lens as a Major Risk Factor for Microbial Keratitis in School Children

Research
The Lee Wing Kit Advanced Ophthalmic Training and Education Centre Opens Today

The Lee Wing Kit Advanced Ophthalmic Training and Education Centre Opens Today

Donation

Our Expert List

Many experts under the Faculty of Medicine are available for media interview.
Please click here for the expert list or contact us.