I’m fascinated by the educational opportunities e-learning is bringing into our homes and classrooms. I’m thrilled when I see how engaged and motivated my own five-year-old daughter is when she’s working on a computer designed for kids. But, as a parent, I’ve had my concerns, too. Will staring closely at the computer screen harm her eyes? Is it better for children to read on paper than on screen? E-learning is still relatively new; when I started asking these questions in 2009, there hadn’t yet been any direct studies on computer use and the impact on children’s vision.
Fortunately, I’m in a position to find out the answers. I specialize in the perceptual aspects of the computing experience, including hearing, touching, and seeing (not tasting or smelling—yet). As a senior human factors engineer in one of Intel’s user experience research groups, I conduct research on Intel® Learning Series (ILS) computers, which are designed especially for children. I was able to initiate a series of studies with Pacific University in Oregon to look at children’s performance and comfort when using computers. Together, we were on a mission to answer key research questions to improve the overall e-learning experience for children, starting with their visual experience.
Does Screen Viewing Impact Children’s Vision?
We began our research by identifying the visual demands placed on children while working on computers. We called on the experts and asked, “Does screen viewing impact children’s vision?” First on our list was Jeffrey Anshel, OD, president of the Ocular Nutrition Society and an authority on the topic. He answered, “The good news is that there isn’t any proof that computer use causes long-term eye health problems.”
Dr. Anshel went on to explain that the potential for visual strain from computer screen viewing is often a matter of short-term discomfort, not long-term detriment to eye health. “Of course, if a person focuses close up on anything—a computer screen, TV, even a book printed on paper—for 20-30 minutes or longer without taking a visual break, that person may experience some visual strain,” he added. “The symptoms could be eye discomfort, fatigue, blurred vision, and headaches. There’s even something called Computer Vision Syndrome (CVS), which is a compilation of symptoms that arise from extended viewing, technically when the sustained demands of the task exceed the abilities of the viewer.”
I discussed these issues with my research colleague, James Sheedy, OD, Ph.D., the director of the Vision Performance Institute at Pacific University and a leading specialist on vision and computer displays. He pointed out, “We saw a lot more visual strain symptoms with the old CRT displays. The CRTs flicker, contributing to eye strain, although now you can usually increase the refresh rate on those screens, so it’s less of an issue. The CRTs are also prone to reflections, which decrease contrast and legibility. Plus, the CRTs are bulky in size, so it’s harder to place them on a surface where they’ll allow for a safe viewing distance or provide the proper viewing angle. But the high-quality displays of the LCD screens don’t flicker at all, so they’re much easier on the eyes. They’re thin and easy to position, and they tend to have anti-glare screens, at least as an option.”
Most of the newer computer screens today, and all the screens used in my company’s classroom PCs, are LCDs. But I was determined to zero in on any possible factors contributing to children’s visual discomfort and strain, even with LCD screens.
I turned to the research my team had previously conducted, in particular our observations that children use computers quite differently than adults. An adult will typically sit down at a computer and automatically adjust for less-than-ideal conditions (for example, raising the chair, brightening the screen a bit, or putting on reading glasses). A child, on the other hand, sits down at a computer and ignores any signs of discomfort or circumstances that could result in visual strain. As Dr. Sheedy pointed out, “Children are wonderfully adaptable. But unfortunately, they also tolerate poor viewing conditions like screen glare or inadequate lighting in the classroom. And they sure don’t care about proper posture when they’re using the computer!”
I agreed, “Not to mention they don’t think to rest their eyes like adults do. Or even blink!” “That’s right. And even if something is uncomfortable, most children will simply avoid doing it,” Dr. Sheedy said. “Besides, children aren’t aware of their own vision limitations, like an adult would be, whether it’s because of poor user conditions or their own vision impairment.”
I came away with an idea my team could pursue immediately—incorporating vision-screening software into computers. That way, teachers and parents could quickly test a child’s visual acuity and be able to determine whether the child’s environment needed to be adjusted or if the child had a vision impairment that needed correcting.
Studying Children and e-Reading
Based on these early conversations with vision experts, research questions were honed and a research plan on the effects of e-reading on children’s vision relative to the factors surrounding children’s all-around comfort when using computers—visual and otherwise—was developed. The team then embarked on a series of studies in collaboration with Dr. Sheedy’s team of vision experts at Pacific University, led by Shun-nan Yang, Ph.D. Our research looked at several aspects of children’s visual comfort and reading performance, including studies on the effects of font size and display quality, factoring in screen luminance and contrast. We also incorporated studies to determine whether frequency of breaks and reading posture interact with viewing distance and visual discomfort when e-reading on handheld devices.
Our first studies, on children’s comfort and performance while reading using LCDs compared to reading on paper, were designed specifically for second to eighth grade children. We recruited fifty children and screened our young participants for visual acuity and reading comprehension skills. We then carefully customized all study instructions and selected reading materials to be age appropriate. The computer and paper displays were set in a fixed position to standardize the visual angle of the display and to set the starting visual distance. Chair and table heights were adjustable and made ergonomically correct for each individual.
During the studies we measured reading performance (word recognition, speed, and comprehension) as well as viewing distances and visual comfort. Visual comfort was gauged using both a self-reporting rating scale and an objective electromyography (EMG), which measured the muscle “squint” activity around the eye.
We learned that the novice readers (the younger children) had consistently closer viewing distances, regardless of their visual acuity. Dr. Yang articulated our hypotheses, “These readers may be inherently poorer at visual encoding because they are just learning how to read, so they need a closer viewing distance regardless of font size or display quality. Their closer viewing distances may also be the result of the visuo-ocular response they habitually adopt; they lack the ability to strategically adjust their viewing distance in relation to font size and display condition.” We all agreed that more studies were needed to test these hypotheses.
With the experienced readers (the older children) in the group, only those with poor visual acuity adopted a shorter viewing distance. When the display quality was less than ideal, it made their viewing distances even shorter. Future studies would likely reveal additional visual factors surrounding text display that could result in a closer viewing distance. We did observe that the more experienced readers appeared to be able to adjust their viewing distances in relation to text and display changes, so they may benefit the most from display quality improvements. It became clear that correcting their vision impairments would allow them to adopt longer viewing distances, which would help alleviate the minimal, but notable, visual strain and discomfort they experienced.
Our findings highlight the interplay of individual visual capacity and display quality when determining developmental readers’ visual comfort and performance. After careful analysis, we were happy to report that children with good vision could read as well on LCD computer displays as on paper, without notable differences in viewing distances and the resultant visual discomfort.
I was relieved to learn that e-reading doesn’t appear to cause additional visual strain for children with adequate vision. Any visual discomfort that was reported was very minor. But there is always room for improvement. We took copious notes on factors to research further for the development of new screen technologies.
Exploring Other UX Factors
The outcomes of our first e-reading vision studies on children with 20/20 vision were interesting. We learned that when screen luminance and contrast are adjusted properly, children can comfortably view the screen from farther away. We had also learned about variable lighting and other conditions that make classrooms unique compared to home and office environments. This influenced the latest features being developed for our classroom PCs, like sensors that could automatically detect light levels surrounding the computer and adjust accordingly.
We continued to brainstorm new computer screen design specs and setting options based on our findings. The plan was to fast track one idea for our classmate PCs—creating software that would provide pop-up reminders every twenty minutes or so to remind kids to take visual breaks and to focus on something far away, ideally twenty feet away, for twenty seconds.
In addition, a longitudinal e-reading pilot program was in the works. Short-term usability results can be so different when children are involved. Children love the e-learning experience because of technology’s “wow” factor, so they may not report long-term discomfort or other effects. Therefore, we were preparing for a pilot study in the classroom, comparing reading on computers versus reading on paper. The goal was to follow the same students from second through sixth grade to gain a long-term perspective on the effects of e-reading on children.
Improving Children’s e-Learning Experiences
I’m confident that the growing—and inevitable—integration of e-learning into the classroom will be a positive, exciting development. We’re off to a good start with the vision and other research we’re conducting with our partners, but there are many more factors to be studied and improved upon. Research on the effects of children’s long-term computer use is still extremely limited; there remain key research questions that need to be answered by all of us.
Computer industry influencers and other companies leveraging UX designers and developers need to continue to set new standards for the industry. We must invest in e-reading studies, make recommendations, and initiate improvements. All of us have to be proactive about sharing our research findings. As user experience professionals, we need to step forward and do all we can to advocate for children and education.Rina Doherty 是 Intel 用户体验组的一位资深人因工程学工程师，她对儿童的视觉与计算机屏幕浏览进行开拓性的研究。作为用户体验研究人员和尽责的家长，她重视与儿童浏览计算机屏幕的时间增加相关的视觉舒适性问题，而将在线学习的好处放在次要地位。
文章全文为英文版上級人間工学エンジニアでIntelのユーザエクスペリエンスグループの一員であるリナ・ドーティ（Rina Doherty）が、子どもの視覚とコンピュータスクリーンの使用に関する先駆的調査を紹介している。 ユーザエクスペリエンスの研究者、そして問題に関心を寄せる親として、彼女は、子どものコンピュータモニターの使用増加に関連した視覚的な快適さの問題と、eラーニングのメリットとを比較検討している。