Modern technology has revolutionized the way we consume information, but for some, such as people with presbyopia or other visual impairments, reading on smartphones and screens can become a daily challenge.
In this article, we will explore the impacts of presbyopia and visual impairments on digital reading as well as practical tips to improve this experience, highlighting specific challenges in terms of UX (user experience).
Understanding the different visual impairments
Certain visual impairments can alter the way a person perceives details in their environment. Sometimes these particularities cause difficulties when reading, using screens or everyday visual interactions. Having a good understanding of these visual nuances is valuable for adjusting technologies and environments, which can help improve quality of life and provide an optimized visual experience for everyone.
Presbyopia
Presbyopia is an age-related disability that usually occurs around midlife. It manifests itself by a loss of flexibility of the lens of the eye, making it difficult to focus on nearby objects. People with presbyopia have difficulty reading small print up close, such as that on smartphone screens, computer screens or even books. They may experience increased eye fatigue when reading on these screens for extended periods of time.
Myopia
Myopic people see nearby objects clearly but have difficulty seeing distant objects clearly. This can cause difficulty reading texts at a normal distance on a screen (televisions, advertising screens, etc.). Eye fatigue and headaches can also be common symptoms in people with nearsightedness after prolonged use of screens.
Hyperopia
Unlike nearsightedness, farsightedness causes vision of near objects to be blurry while distance vision generally remains clear. People with farsightedness may have difficulty reading up close without compensation (glasses). This can lead to increased eye strain and difficulty concentrating when reading on a screen for prolonged periods.
Astigmatism
Astigmatism is characterized by an irregular curvature of the cornea (external astigmatism) or lens (internal astigmatism), which causes blurred vision at all distances. This can make on-screen reading more difficult if proper correction is not applied. People with astigmatism may experience sensations of eye fatigue, burning, dryness during prolonged use of screens, headaches or even distortion of lights (for example: the lights of opposing vehicles when driving at night).
Cataract
Cataract is a clouding of the lens of the eye, leading to blurred vision and sensitivity to light. People with cataracts may have difficulty reading or seeing details clearly on a screen. They may experience increased glare and decreased color sharpness when using digital devices.
Water Lily Pond, Claude Monet (1899): without cataract
Water Lily Pond, Claude Monet (around 1923): with cataract
Color perception deficiency
Some individuals have partial or complete color vision deficiency, which may affect their ability to distinguish certain visual elements on screens that rely on color differences to convey information. This can lead to difficulty reading, navigating, or interpreting visual content on digital devices.
Difference between computer screen and smartphone
Reading distance and accommodation
When reading on a computer screen, the typical distance is around 50 to 70 centimeters, which allows the eye to focus comfortably for extended use. On the other hand, with a smartphone, the reading distance is considerably reduced, often around 30 centimeters or less. This proximity requires an increased effort to accommodate the eye to maintain the sharpness of the characters and details displayed. This can lead to faster visual fatigue, especially for people with visual impairments like presbyopia.
Character size and visual constraints
Computer monitors generally offer a larger display area, allowing a more comfortable character size for reading. In contrast, smartphones have smaller dimensions, which can result in a significant reduction in character size. Users often need to enlarge text for comfortable reading, which can compromise the overall user experience and increase visual fatigue.
Brightness and visual adjustments
Smartphones tend to be used in varied environments, which may result in frequent adjustments to screen brightness for optimal visibility. Rapid changes in brightness and contrast can be more tiring for the eyes, especially for people sensitive to these variations. Additionally, contrast and brightness settings on smartphones may not always be optimal for extended reading, requiring constant user adaptation.
Symptoms and risks associated with heavy screen use
Studies on the influence of screens on visual functions have revealed several common symptoms among heavy users. These symptoms include eye fatigue, eye pain, feeling irritated, blurred vision, watery eyes, or red eyes. Additionally, long hours of screen exposure can lead to musculoskeletal disorders like neck, back, and shoulder pain, as well as issues like carpal tunnel syndrome. Contact lens users may also be more likely to develop dry eye. It is important to note that these symptoms may be exacerbated by other factors such as indoor air quality, including the presence of dust, pollens, aerosols or irritating chemical compounds.
Prolonged smartphone use can also affect ocular convergence, which is the ability of the eyes to turn inward to maintain binocular vision. When we stare at a smartphone screen for long periods of time, our eyes are often focused on a fixed point at a relatively close distance. This can cause undue strain on the eye muscles responsible for convergence, which can cause additional eye strain, headaches, and difficulty focusing.
Impacts on the UX of reading on smartphone and screen
Reading on a smartphone or screen can pose significant challenges for users with visual impairments. For example, small font size or lack of contrast can make digital interfaces less accessible, negatively impacting user experience (UX). Additionally, prolonged reading on a screen can lead to increased eye fatigue in these individuals.
Difficulty reading elements due to small size or low brightness can also affect the smoothness of reading and, therefore, the user experience. Additionally, poorly designed visual elements can lead to misunderstandings, reducing the effectiveness of communication and the overall quality of the UX.
Tips to Improve the Reading Experience
To improve the reading experience for people with visual difficulties, several practical tips can be followed. Therefore, it is recommended to:
- Adjust the text size to make the characters more readable.
- Adjust the contrast and brightness of the screen to reduce eye strain.
- Use apps specifically designed for visually impaired people, which can also contribute to a better user experience.
- Apply the “20-20-20” rule by taking regular breaks to rest your eyes. It is a recommended practice to maintain good visual health during prolonged use of digital devices.
The “20-20-20” rule is a recommended practice to reduce eye strain related to prolonged screen use. It involves taking regular breaks following the following pattern: every 20 minutes, look at something 20 feet away (about 6 meters) for at least 20 seconds. This technique helps relax the eye muscles used by prolonged focusing on nearby objects, such as characters on a screen, and reduces visual fatigue. This helps maintain visual comfort and prevent the harmful effects of prolonged exposure to screens on the eyes.
References:
- Study on the influence of screens on oculomotor and accommodative functions by Tristan Jurkiewicz, Célia Essertaize, Genna Meyssonnier, available on ScienceDirect.
- Study on ocular stress induced by screens: Analyzes of functional symptoms and binocular balance in intensive users by E. Auffret, M. Mielcarek, T. Bourcier, A. Delhommais, C. Speeg-Schatz, A. Sauer, available on ScienceDirect.
- Computer Vision Syndrome Study (CVDTS) by Mark Rosenfield , published on PubMed.
Florianne Nollet, UX-UI designer consultant at UX-Republic
