Pandemic Eye Strain: Managing The Long Term Effect of Screen Time on Children’s Eye Health and Vision

Since stay-at-home guidelines associated with the COVID-19 pandemic were instituted in March 2020, educators have relied on digital schooling capabilities to keep meeting educational goals. A quick rollout of Zoom classrooms and web-based homework platforms helped keep students safe from the spreading pandemic. For many children, this substitute learning model, or a hybrid approach, persisted for the remainder of the 2019-2020 school year, and lasted the entirety of the 2020-2021 school year. As the 2021-2022 school year begins and educators continue to keep student and faculty health top-of-mind amidst the spread of the even more transmissible Delta variant of the virus, some schools are already seeing a return to a digital/in-person hybrid model. 

Although young people’s use of digital devices was high even before the pandemic, this digital schooling has exponentially increased the amount of hours American children have spent with their eyes on the screen. All that comes with markedly increased near work, exposure to blue light, and severely reduced blinks, which in turn could permanently affect developing eyes.    

“Researchers still need … a lot of data to understand fully the impact of the pandemic on myopia progression and eye health overall,” explains Neeraj K. Singh, BSOptom, MPhil, PGD (Epidemiol), an associate instructor and PhD scholar at Indiana University’s School of Optometry. However, Dr Singh said the most common problems associated with increased screen time are eye strain, dry eye diseases, and myopia progression. All these problems are becoming more widespread. Myopia alone is primed to affect nearly a third of Americans by 2050.¹

With the pandemic adding to these concerns, eye care physicians are exploring ways to prevent an ocular disease onslaught and offer guidance to patients, parents, and educators that can help undo some of the damage and keep children’s vision strong for years to come.

Drying Out

In a study published in the American Journal of Ophthalmology, Sandra Lora Cremers, MD, FACS, explored the association of children’s daily screen time with severe meibomian gland atrophy. Dr Cremers, an ophthalmologist at Visionary Eye Doctors in Washington D.C. and a surgeon at Johns Hopkins Suburban Hospital, has long expressed concerns regarding extended electronic screen time, blink rates, and intake of blue light.²

Her team’s research found 86% of the 17 patients with severe meibomian gland atrophy spent at least 4 hours per day looking at digital screens.² Cumulative hours of electronic screen use per day (CHESUD) appeared to be positively associated with the increase in combined meibography scores in both unadjusted and adjusted analyses (OR: 2.81; 95% CI, 1.66 to 4.77, 2.74; 95% CI, 2.39 to 5.41, respectively).²

“Our paper was about data that was obtained before COVID hit,” Dr Cremers said. “We are very concerned that students spending more time on screens are blinking less, which is causing the meibomian gland oil to dry up even faster. We won’t know the full effect of this probably for a few more years.”

She added that hours worth of blue light exposure each day is another concern, and recommended the use of blue light filters.

“While there are published papers showing blue light is potentially damaging to the macula, there are no published reports showing causation of blue light with damage to the ocular surface or meibomian glands: though it may take years to prove causation,” she said. “By that time, it might be too late.”

Another study — a 2021 report published in Eye & Contact Lens — evaluated the results of a cross-sectional survey of University of Valencia students in Spain whom researchers classified as “online students” (n=523) or “in-person students” (n=289) based on the number of hours they spent in online lectures.³ Through the survey, the students completed the Ocular Surface Disease Index (OSDI), the Dry Eye Questionnaire (DEQ-5), the CL Dry Eye Questionnaire (CLDEQ-8), and questions regarding dry eye disease (DED) risk factors in the TFOS DEWS II Epidemiology Report.⁴

The research shows that the online students had higher OSDI scores (P =.029) and that the hours of online lectures per week were independently associated with having a positive OSDI score (P =.022).³

When they investigated prevalence of DED risk factors, they found through multivariate logistic regression that attending more online lectures per week, having higher levels of stress, and using a greater number of electronic devices at the same time were independently associated with dry eye symptoms (P ≤.045 for all).

“All things considered, online students showed a significantly lower prevalence of various potential DED risk factors than in-person class attendees,” according to the researchers. “Nevertheless, taking online lessons was associated with having higher dry eye symptoms scores, with the likely reason behind this apparent incongruity being the greater digital display usage by online students, which was typical of participants with a positive OSDI score and was associated as a potential risk factor for having dry eye symptoms.”

Near Work And Nearsightedness

Alina Dumitrescu, MD, a clinical associate professor of pediatrics, ophthalmology, and visual science at University of Iowa Hospitals and Clinics, said virtual schooling during the pandemic has added, on average, an additional 2 to 3 hours of screen time a day. Evidence regarding the effect of screen time on ocular health is “inconclusive” since the pandemic has “created several interrelated issues,” including delays in seeking routine medical care, which led to delays in updating or acquiring prescription glasses, or treatments for eye diseases, Dr Dumitrescu said.

She also noted a distinction between “school-age myopia” and “juvenile progressive high myopia.”

“[School-age myopia] is very common and will usually progress until the teenage years unless measures to prevent progression (pharmacological, orthokeratology, or peripheral defocus) are put in place, and ‘juvenile progressive high myopia” (early-onset – before school, with high myopia) … is less common but has the highest risk of progression and complications and may not respond to the same treatments,” Dumitrescu said. “Often, juvenile progressive high myopia has an underlying cause like a collagen disorder or retinal dystrophy.”

The precise mechanisms of myopia are not fully known; however, most agree that the condition is likely caused by a combination of genetic and environmental factors. Among those environmental factors is the relationship between near work and myopia. A British Journal of Ophthalmology study published in 2020 shows that working at a distance of less than 20 cm, especially in low light conditions, is a risk factor for myopia.⁵

Additional research shows a distinct connection between the home confinement of the pandemic (with its accompanying screen use) and an increase in the systemic rates of myopia in children. A JAMA Ophthalmology study looked at children between ages 6 and 8 years, an important period for the development of myopia.⁶ For this age group, “refractive status may be more sensitive to environmental changes than older children,” the investigation says.⁶ This study used school-based photoscreenings to uncover a -0.3 D shift in myopia among 194,904 tests conducted in 123,535 children. “This substantial myopic shift was not seen in any other year-to-year comparison, making the cause possibly due to the unusual occurrence of home confinement in 2020,” according to the investigators.⁶ 

The report emphasizes that age is a major factor in myopic change. For the youngest group studied (6-year-old children) myopia prevalence increased by approximately 3 times higher in 2020 than in other years. For 7-year-old participants, the increase was twice as high as previous years and, in the 8-year-old group, the increase was only 1.4 times higher than in the past. 

“Such a substantial increase in the prevalence of myopia was not seen in the older age groups (9-13 years), despite the fact that the older children (grades 3-6) were offered more intense daily online learning courses (2.5 hours) compared with the younger students (grades 1-2, 1 hour daily),” according to the report. “These findings led us to a hypothesis that younger children are more sensitive to the environmental change than older children. In the setting of this specific study, the period of environmental change (home confinement) was 4 months and the children who appeared to be affected were aged 6 to 8 years.”⁶

These findings may mean that mitigation strategies are particularly warranted for individuals younger than 9 years old, and are especially important for younger patients.

Healthy Ocular Habits

Research shows that when children spend more time outside, they may be able to reduce their risk for myopia progression. As an example, researchers in Taiwan found that the Yilan Myopia Prevention and Vision Improvement Program, which encouraged children aged 5 and 6 years to spend at least 2 hours outside each weekday as a myopia prevention strategy, reduced the prevalence of myopia among age cohorts in just 2 years, by 5.2% from 2014 to 2020.⁷

In addition to recommending patients spend as much time outdoors as possible, Dr Cremers said ophthalmologists, optometrists, parents, and teachers should encourage students to take frequent breaks from their screens. If it is necessary to use a device for multiple hours, individuals could try using dictation and text-to-speech reading features or closing their eyes while typing for part of that time, Dr Cremers suggested.

“If parents and educators intervene now, we can slow down this process of the myopia epidemic,” Dr Cremers said.

Another option for students to mitigate screentime vision damage is to employ the 20-20-20 rule, Dr Singh explained. That method asks  patients to consciously spend 20 seconds looking at something at least 20 feet away every 20 minutes of screen time. Schools conducting virtual education could hold 15- to 20-minute “no gadget breaks” after each hour of online learning, which could remain as part of the school day once in-person schooling resumes, he suggested.

To limit eye strain, children should be encouraged to use smart devices with a  minimum screen size of 13 inches, and to use them while exposed to natural light if possible, Dr Singh said. If they need to use them inside, they should use ambient light, he said.

The American Association for Pediatrics Ophthalmology and Strabismus provides a Media Time Calculator on its website that parents can use to help visualize the impact of screen time.

In The Exam Lane

Ophthalmologists evaluating children should record biometric data, including their eyeball length at each appointment to track the size to aid in determining the etiology of the myopia, to supplement diagnostic questionnaires, Dr Singh said. 

“Kids will not come and say ‘my prescription is declining,’” Dr Singh said. But a few tell-tale signs could indicate to parents it is time to bring them in to review their vision.

Dr Cremers agreed, adding that any time a child “notices” symptoms of strain, discomfort or dryness in their eyes, or changes to their vision, it is time to see a doctor. 

“It is totally abnormal to notice your eyes,” Dr Cremers said.

That’s when the testing begins. In addition to comprehensive eye and vision exams, Dr Cremers also supports the application of tools such as meibography to monitor the health of the meibomian glands and tear film layers. 

“Anyone who views an electronic screen more than 4 hours a day should likely get a 4-lid meibography,” she said. “If there is any gland atrophy, meibography should be repeated every year as the patient begins treatments to slow down the gland loss, depending on age.” Dr Cremers said. Patients with severe meibomian gland loss, may need to be referred to an eye surgeon or cornea specialist, she added.

“The COVID-19 pandemic has affected life at many levels, and pediatric patients are no exception,” Dr Dumitrescu said. “From extended indoor and screen time to lack of appropriate social interaction, to difficulties wearing their glasses at the same time with the masks due to fogging, all are contributing and will have some effect. If nothing else, creating bad habits and social anxiety is significant enough. We will have to monitor closely for an increase in myopic refractive errors or for progression [in] kids that already have myopia.”

References

1. Bullimore MA. The underestimated role of myopia in projected visual impairment in the United States. Invest Ophthalmol Vis Sci. 2021;62(8):2325.   

2. Cremers SL, Khan ARG, Ahn J, et al. New indicator of children’s excessive electronic screen use and factors in meibomian gland atrophy. Am J Ophthalmol. Published online April 12, 2021. doi:10.1016/j.ajo.2021.03.035 

3. Talens-Estarelles C, García-Marqués JV, Cervino A, et al. Online vs in-person education: evaluating the potential influence of teaching modality on dry eye symptoms and risk factors during the COVID-19 pandemic. Eye Contact Lens. 2021;00:1-8. doi:10.1097/ICL.0000000000000816

4. Wolffsohn JS, Arita R, Chalmers R, et al. TFOS DEWS II diagnostic methodology report. Ocul Surf. 2017;15:544-79. 

5. Wen L, Cao Y, Cheng Q, et al. Objectively measured near work, outdoor exposure and myopia in children. Bri J Ophthalmol. 2020;104(11):1542-1547. doi:10.1136/bjophthalmol-2019-315258

6. ​​Wang J, Li Y, Musch D, et al. Progression of myopia in school-aged children after COVID-19 home confinement. JAMA Ophthalmol. 2021;139(3):293-300. doi:10.1001/jamaophthalmol.2020.6239

7. Yang YC, Hsu NW, Wang CY, et al. Prevalence trend of myopia after promoting eyecare in preschoolers: a serial survey in Taiwan before and during the COVID-19 pandemic. Ophthalmol. Published online August 20, 2021. doi:10.1016/j.ophtha.2021.08.013