None of the participants suffered from any eye diseases (e.g., cataract). Effects of Contrast Polarity on Visual Acuity and ProofreadingĬosima Piepenbrock and her colleagues at the Institut für Experimentelle Psychologie in Düsseldorf, Germany studied two groups of adults with normal (or corrected-to-normal) vision: young adults (18 to 33 years old) and older adults (60 to 85 years old). In particular, we will focus on two articles that involved two different types of tasks: one, published in 2013 in the journal Ergonomics, looked at visual acuity and reading performance, and the other one, published in 2017 in Applied Ergonomics, investigated performance for a glanceable-reading task - the quick reading of 1–2 words that people often engage in when they interact with a mobile phone, a smartwatch, or a car dashboard and that is involved in activities such as checking directions or attending to a notification. Yet, several more recent studies contradict that initial finding. Normal-Vision UsersĮarly studies conducted in the 1980s seemed to point out that, for people with normal vision or corrected-to-normal vision (i.e., wearing appropriately prescribed glasses or contacts), the contrast polarity did not affect visual performance. On the other side, as we get older, we become more susceptible to glare, and glare is particularly likely under bright light. Too small pupil sizes mean that too little light enters the eye, which impairs our ability to read or detect text, especially in low ambient light (for example, at night). (Camera apertures work exactly in the same way: a photo taken at f/2.8 will have a narrower depth of field and thus more blurring than one taken at f/16.)Īs we age, the pupil decreases in size. Smaller pupil sizes make the eyes less susceptible to spherical aberrations (in which the image appears unfocused) and increase the depth of field, so people don’t have to work so hard to focus on the text, which, in turn, means that their eyes are less likely to get tired. By default, the human pupil changes size depending on the amount of light in the environment: when there is a lot of light, it contracts and becomes narrower, and when it’s dark, it dilates to allow more light to get in. The human pupil is the gateway to the retina: through it, light reaches the eye. The Human Pupil Is Sensitive to the Amount of Light In order to understand how, let’s briefly review some basic information about the eye pupil and how it reacts to the amount of light in the environment. But the amount of light in the environment influences not only power consumption, but also our perception.

Negative contrast polarity (dark mode) denotes the combination of light (e.g., white) text on dark (e.g., black) background.ĭark-mode displays emit less light than light-mode ones (and, because of that, they might extend battery life).

Positive contrast polarity (light mode) refers to dark-font text on light background.

I will share these findings with you.īut first, let’s make sure we’re all on the same page by defining some vocabulary.ĭefinition: Contrast polarity is a term used to describe the contrast between the text and the background: However, these questions prompted me to do a review of the academic literature on whether dark mode has any benefits for users - with normal vision or not.

I must say upfront that NN/g has not done its own research on dark mode. It’s a question that I also got several times from attendees to our UX Conference. Recently, spurred by the introduction of dark mode in IOS 13, a reporter asked me to comment on the usability of dark mode and its popularity as a design trend.

Change macbook from dark to light