Is E-Ink Better For Your Eyes? A Review of the Literature

Several manufacturers of E-ink devices, including E-ink themselves, infer that their screens are better on the eyes than LCD or OLED screens.

…users of E Ink displays have said that they do not have the same eye fatigue as with LCDs when reading for long periods of time.
E-Ink (https://www.eink.com/tech/detail/Benefits_4) Accessed 4th Jan 2023

Comfortably read PDFs or ebooks for hours on end without backlight, glare, or eye strain.
reMarkable (https://remarkable.com/) Accessed 4th Jan 2023

Access your digital library and read eBooks comfortably for hours without eye strain
Supernote (https://supernote.com/) Accessed 4th Jan 2023

The Tab Ultra has 36 bulbs that light up the screen from the front, preventing light from entering your eyes directly and reducing eye strain.
Boox (https://shop.boox.com/products/tab) Accessed 4th Jan 2023

In this article, I will investigate if there is any scientific grounding for these claims.

Table of Contents

Method

I conducted a search relating to E-ink screens and eye strain using Google Scholar to gather a collection of academic papers in this domain. I then used software from CitationTree.org and ConnectedPapers.com to find related papers to expand the knowledge base.

Next, I read through each of the papers and analysed their content whilst making notes of the findings. These notes were then used to inform the writing of this article.

Literature Review

The most striking result of this research was that there had been very few extensive studies that explore the differences between E-ink and LCD displays in relation to eye strain.

Links between OLED/E-INK screens and Ocular Surface Disorder

The most recent and useful study was conducted in 2021 by Yuan et al. ^[1] and used various tests to investigate links between the use of both OLED and E-ink smartphone screens and Ocular Surface Disorder (OSD). OSD refers to damage to the cornea and conjunctiva, which can lead to diseases such as Dry Eye Syndrome and Blepharitis.

Their results suggest that E-ink smartphone screens are less likely to cause OSD than OLED screens.

…reading on an OLED screen can cause ocular surface disorder and obvious subjective discomfort, whereas reading on an eINK screen can minimize ocular surface disorder in both dark and light environments.
Yuan et al. 2021

This is also the largest study, which used 119 volunteers.

E-ink vs LCD vs Print: Effects on visual fatigue

A 2013 study by Benedetto et al.^[2] compared the effects on visual fatigue when reading on E-ink screens, LCD screens and printed text. Four measures were used to assess visual fatigue; Critical Flicker Frequency, Eye Blink, Visual Fatigue Scale, and subjective preference.

The study found that the LCD screen contributed to more visual fatigue than both the E-ink screen and the printed text.

Results from both objective (Blinks per second) and subjective (Visual Fatigue Scale) measures suggested that reading on the LCD (Kindle Fire HD) triggers higher visual fatigue with respect to both the E-ink (Kindle Paperwhite) and the paper book. The absence of differences between E-ink and paper suggests that, concerning visual fatigue, the E-ink is indeed very similar to the paper.
Benedetto et al. 2013

It should be noted that only a small sample of 12 participants was used in this study.

E-ink vs Print: Comparison of eye movement

Several studies were published by Siegenthaler et al.^[3] in 2011 and 2012 that compared reading on E-ink screens, LCD screens and print.

The first study compared reading processes on e-ink devices and paper in terms of eye movements. They concluded that there was little difference in eye movement between the two media.

…reading behavior on e-ink-displays is very similar to the reading behavior on print.
Siegenthaler et al. 2011

E-ink vs LCD: Effects on fatigue and visual strain

The second study by Siegenthaler et al. ^[4] explored the effects of visual strain and fatigue when reading on E-ink and LCD screens. The measures used to assess this were; subjective (visual) fatigue, a letter search task, reading speed, oculomotor behaviour and the pupillary light reflex.

This study concluded that in terms of the aforementioned measures, there were no statistical differences between E-ink and LCD screens.

Results suggested that reading on the two display types is very similar in terms of both subjective and objective measures.
Siegenthaler et al 2012

Just 10 subjects were used in this study.

E-ink vs LCD: Comparison of eye movement

The third study by Siegenthaler et al. ^[5] compared reading behaviour (in terms of eye movement) between E-ink and LCD screens. The results showed that there was no comparable difference between these two types of screen.

Combined with the first study, this also suggests that there is no difference in eye movement across all media (E-ink, LCD and Print).

The analysis of eye movement data shows that reading behaviour on LCDs (tablets) is very similar to the reading behaviour on e-ink displays. There was no significant difference in fixation durations which gives evidence that participants didn’t have more difficulties with reading on LCDs com-pared to e-ink displays.
Siegenthaler et al 2012

This study used 12 participants.

Comparison of oxidative stress response of in vitro retinal cells exposed to blue light from emissive versus reflective displays

Since I originally wrote this literature review, a study was conducted that tested the stress on retinal cells caused by spectra from LCD and E-ink screens^[6]. Their findings were:

Cells accumulated ROS two to three times as fast when being exposed to backlit
LCD compared to frontlit EPD, each operated in the same light mode (day or night).

Extrapolating from the data, it would seem that devices that cause ROS accumulation at a lower rate(i.e., EPD with frontlight) can be used for longer times before the
same levels of ROS are reached.
Wang et al 2023

This would suggest that e-ink screens, even with a frontlight, are less likely to damage eyes following prolonged use than LCD screens. However, it is worth noting that two of the lead researchers in this study are employed by E-ink corporation. A good overview of this study can be found here.

Limitations of this literature review

Although I have a reasonable layperson’s understanding of the scientific method and screen technologies, I have not had formal training at the undergraduate level. I also do not have access to extensive academic research databases – only what is freely available online. Neither have I the medical knowledge or experience to critically evaluate if the tests performed in the studies are appropriate; however, the fact that they have been published for peer review would suggest that they stand up to scientific rigour.

Another limitation is that very few studies have been conducted in this area and so it is not yet possible to say with any certainty that E-ink screens are better on the eyes than LCD and OLED screens, although the evidence does suggest this.

I am surprised that EINK (the company) has not funded more independent research in this regard because a positive result would mean that they and their partners could categorically say that their screens are better for the eyes than their LCD and OLED counterparts, which would be a great boon for the marketing and branding.

The cynic in me thinks that there may be a good reason for this – perhaps they already know that they would not be able to prove this one way or another due to either a lack of methods for accurately measuring eye strain, studies having to be carried out over the long term (decades) or that they already know there are no health benefits of an E-ink screen over an LCD or OLED screen.

This literature review could be improved if it was reviewed and revised by somebody with more academic knowledge and experience than myself. In addition, a lot more independent research must be carried out because the current body of evidence does not sufficiently answer the question.

Conclusions & Discussion

Seigenthaler et al.’s studies are, in general, quite small, comprising around 10 participants, which makes it difficult to understand how the results might be statistically relevant. Similarly, Benedetto et al.’s study used 12 participants.

In addition (and perhaps due to the small sample sizes) these studies had conflicting results, with Benedetto et al. concluding that LCD screens were more likely to cause visual fatigue and Seigenthaler et al. concluding that there was little difference.

The research by Yuan et al. provides us with the best understanding of the effects of different screen types on ocular health, with E-ink screens providing a similar experience to reading a printed book.

Wang’s study only approaches the issue from a lab setting, and does not take into account the complexities of real-life scenarios. In addition, with two scientists from E-ink corporation being involved, there could possibly have been some commercial influences in the results or publications.

In conclusion, although the current evidence suggests that E-ink screens are better for the eyes and may reduce eye strain, there has currently not been enough research into this subject to provide an indisputable answer.

Therefore, it should be understood that when manufacturers of E-ink devices state that their screens reduce eye strain, this is not backed by any robust empirical scientific evidence (although they may be using anecdotal evidence, such as customer comments). Personally, I believe that when manufacturers make such claims, they should reference their sources so that consumers can make an informed choice.

Hopefully, with E-ink devices becoming more popular in consumer markets, funding will be available to research this subject further.

Bibliography

Yuan K, Zhu H, Mou Y, Wu Y, He J, Huang X, Jin X. Effects on the Ocular Surface from Reading on Different Smartphone Screens: A Prospective Randomized Controlled Study. Clin Transl Sci. 2021 May;14(3):829-836. doi: 10.1111/cts.12933. Epub 2021 May 3. PMID: 33202098; PMCID: PMC8212737.
Benedetto S, Drai-Zerbib V, Pedrotti M, Tissier G, Baccino T (2013) E-Readers and Visual Fatigue. PLoS ONE 8(12): e83676. https://doi.org/10.1371/journal.pone.0083676
Siegenthaler, E. et al. (2011) “Comparing reading processes on e-ink displays and print”, Displays, 32(5), pp. 268-273. doi: 10.1016/j.displa.2011.05.005.
Siegenthaler E, Bochud Y, Bergamin P & Wurtz P. Reading on LCD vs e-Ink displays: effects on fatigue and visual strain. Ophthalmic Physiol Opt 2012, 32, 367–374. doi: 10.1111/j.1475-1313.2012.00928.x
Siegenthaler, Eva & Schmid, Laura & Wyss, Michael & Wurtz, Pascal. (2012). LCD vs. E-ink: An Analysis of the Reading Behavior. Journal of Eye Movement Research. 5. 10.16910/jemr.5.3.5.
Wang, X, Hertel, D, Garone, LC, Rogers, RA. Comparison of oxidative stress response of in vitro retinal cells exposed to blue light from emissive versus reflective displays. J Soc Inf Display. 2023; 31(3): 112–124. https://doi.org/10.1002/jsid.1191

About the author

Dan Dutton

Website | + posts

Dan Dutton is passionate about E-ink writing tablets, which bring together the pleasure of writing on paper with the power of digital technology. When he bought his first tablet, he realised that there wasn't a lot of unbiased information available for people that were considering buying an E-ink tablet, and so he built eWritable.