We wanted to determine whether reading from a computer, tablet, or smartphone actually worsens eyesight and causes myopia, as many people believe. Thus, we conducted a review to ascertain whether there is any scientific evidence to support this belief.
Let’s first try to comprehend the difference between reading from a paper and an electronic medium from a physics perspective. As per our basic knowledge from school, an object becomes visible when it reflects or emits elementary particles of light, i.e., photons. These photons reach the light-sensitive cells of the retina, and a signal from them is transmitted through a chain of neurons to the brain. When reading from a book page, photons from the sun or an artificial light source hit the page, and black letters absorb photons while white spaces reflect them directly onto our retina. Thus, from a physics point of view, it would be more accurate to state that we do not see the letters as such, but we see the spaces between them. In contrast, when reading from an electronic medium, there is no need for reflected light. The built-in screen backlight emits the necessary amount of photons for us to perceive text or images.
The human eye has the ability to adapt in case of insufficient lighting. Our pupils dilate to allow more light to fall on the retina when we try to examine something in the dark. Similarly, when the illumination becomes brighter, our pupils narrow. If the body’s own capabilities fail to achieve sufficient brightness, we use external adjustment options such as adjusting the lighting to the needs of our vision (turn on brighter light or move closer to the light source). In the case of an electronic medium, we can adjust the backlight power. It is crucial to note that the notion that reading in insufficient lighting harms our eyesight is entirely baseless. To use a memorable analogy from New York ophthalmologist Richard Rosen, “it’s like saying that taking pictures in poor light will damage your camera.”
The largest study of the impact of reading from screens on vision was conducted by scientists from Ohio State University. In 1989, they selected 4,512 children aged 6 to 13 years from different ethnic groups who did not exhibit signs of myopia and monitored their vision for 21 years. The study was designed to identify potential risk factors, and scientists identified time spent in front of the television screen, and later the computer, as one of them. However, the study showed that this factor did not play a significant role in the development of myopia, unlike non-obvious parameters such as time spent playing outdoors. Carla Zadnik, the leader of this study, concluded that children can use computers and other electronic devices as long as they follow basic rules of hygiene and safety.
The amount of time spent reading is correlated with the development of myopia. Prolonged work at a monitor can cause vision deterioration due to the fact that many people neglect the necessary distance between the text and their eyes and fail to take necessary breaks to rest their eyes. Ophthalmologists consider the “20-20-20” rule to be the most important: every 20 minutes of work, individuals should take a break and look at an object that is 20 feet (about 6 meters) away for 20 seconds. By following this rule, we give our eyes the necessary rest, can continue working without experiencing unpleasant symptoms, and avoid harming our vision. Neglecting this rule is likely the reason for “screen myopia” in Dr. David Allamby’s patients.
In 2019, scientists discovered that reading white letters on a black background stimulates unusual information transmission paths for our eyes, which prevents myopia, unlike reading black letters on a white background. Additionally, Japanese scientists observed that chewing gum while reading from a screen can reduce symptoms of eye fatigue, such as dryness, sand-like sensation in the eyes, double vision, and pain, by using different facial muscles.
Therefore, there is no scientific evidence to support the notion that reading from a computer, tablet, or smartphone screen is more detrimental to vision than reading from a paper medium. Nevertheless, it is crucial to adhere to safe work guidelines and consider the recommendation of Japanese scientists to ease eye fatigue by chewing gum and relaxing facial muscles while reading, regardless of whether the material is on a traditional paper or a digital screen.
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