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Bytesize 2: Eye Health

In the second bytesize of the year, the NET Section would like to address eye health as our topic.

Eye Health

Myopia, also known as nearsightedness, is on the rise in students. This has markedly increased since COVID-19 required students to spend an increasing amount of time learning from screens. What does this mean for learning and teaching?

A recent study from by The Faculty of Medicine at the Chinese University of Hong Kong (Zhang et al., 2021) has found that the COVID-19 restrictions implemented during the past 18 months have led to a ‘myopia boom’ among school-aged children in Hong Kong. Restrictions, such as quarantine periods for incoming travellers, prohibition on outdoor activities and group gatherings, and school closures and suspensions of face-to-face classes, have led to increased screen-time and time spent indoors. The screen-time and hours indoors may all be contributing factors to the increased prevalence and rate of myopic progression in young people. Read more details of the study by clicking here.

As teachers, we should pay close attention to students that are having trouble seeing the board. If you notice a student squinting or unnecessarily copying from their neighbour, this could be an early indication of myopia. It’s important that incidents like this are reported to the student’s parents/class teacher so the student can be examined by a professional. 

Methods of slowing down myopia progression rate include using specific prescribed eye drops daily (Atropine), wearing eyeglasses with special lenses, and orthokeratology contact lenses at night.  An eye specialist should be consulted to identify the suitable method depending on each individual to discuss the risks and benefits. It has also been shown that children who spend more time outside and in natural light have less myopic shift than those that spend less time outdoors (Cao et al., 2020).

For those who are lucky not to suffer from myopia, increased screen-time can still lead to eye strain. The main symptoms of eye strain are itchy, tired or burning eyes but other symptoms may include:

  • dry eyes
  • watery eyes
  • blurred vision
  • double vision
  • headaches
  • difficulty keeping eyes open
  • trouble concentrating
  • photophobia (light sensitivity)


It is recommended to consult an eye specialist if you experience any of the symptoms above persistently.

Eye specialists recommend the 20-20-20 Rule for those who are looking at screens or doing a lot of near-work for extended periods of time. The 20-20-20 Rule suggests that every 20 minutes you take a break and look at an object at least 20 feet (6.1 metres) away for at least 20 seconds. The reason being that it takes your eye muscles 20 seconds to fully relax.

Another cause of eye discomfort can be dry eyes, this is especially noticeable in our heavily air-conditioned classrooms and offices in Hong Kong. 

To avoid dry eyes, reduce screen-time if possible and also:

  • make sure that you keep well hydrated throughout the day
  • ensure adequate sleep/rest
  • blink often (when looking at screens, our blinking rate tends to decrease by around 1/3)
  • use artificial tears/lubricating eye drops
  • dim screens and reduce glare from reflections
  • sit further away from your screen, roughly an arm’s length is suggested
  • give your eyes a break and wear glasses for a day from time to time, if you are a contact lens user.

In conclusion, it is important to consider our students’ and our own eye health when we are planning lessons and activities for inside and outside the classroom.

Remember to:

  • Give students regular breaks and use the 20-20-20 Rule.
  • Assign meaningful ‘off-screen’ activities that students can do during their afternoons at home.
  • Observe students for signs of myopia.

Keep an eye out for future Bytesize emails for suggestions of meaningful authentic learning activities!



  • All rights reserved to the copyright owners.
  • Information was available via the links above at the time the webpage was prepared. The links are provided as a convenience and for informational purposes only.



  1. Zhang X., Cheung S.S.L., Chan H.N., Zhang Y., Wang Y.M., Yip B.H., Kam K.W., Yu M., Cheng C.Y., Young A.L., Kwan M.Y.W., Ip P., Chong K.K., Tham C.C., Chen L.J., Pang C.P. and Yam J.C.S. (2021) Myopia incidence and lifestyle changes among school children during the COVID-19 pandemic: a population-based prospective study. British Journal of Ophthalmology. Published Online 2 August 2021. Accessed from 
  2. Cao K., Wan Y., Yusufu M. and Wang N. (2020) Significance of Outdoor Time for Myopia Prevention: A Systematic Review and Meta-Analysis Based on Randomized Controlled Trials. Ophthalmic Research. Published Online 20 August 2020, 63: 97-105. Accessed from


Information gathered from: 


Eye Health Information Sheets for Parents:

Chinese version 

English version   


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