Digital Tablets Can Improve Speed and Ease of Reading for People with Moderate Vision Loss

The iPad 2

An innovative new study exploring the potential of the iPad and other back-lighted digital tablet devices to increase the reading ability and reading speed of persons with low vision was presented at the 2012 American Academy of Ophthalmology Annual Meeting, held from November 10-13 in Chicago, Illinois.

The study, conducted at the Robert Wood Johnson Medical School in New Jersey and led by associate clinical professor Daniel Roth, M.D., concluded that subjects with moderate central vision loss (from macular degeneration) could increase their reading speed by 15 words-per-minute, on average. Using a tablet with a back-lighted screen, however, resulted in the fastest reading speeds for all study participants, regardless of visual acuity.

The Study Summary

From the 2012 Annual Meeting archives:

… researchers found that all of the 100 participants gained at least 42 words-per-minute (WPM) when using the iPad™ tablet on the 18-point font setting, compared with reading a print book or newspaper. A more modest gain of 12 WPM, on average, was achieved by all subjects when using the Kindle™ tablet set to 18-point font.

More Specifics about the Study

From an excellent study summary in The

Methodology: Researchers … identified 100 patients with mild to moderate [central] vision loss. The subjects were randomly assigned three different articles from The New York Times, presented in 10 point font in three mediums: the actual newspaper, a printout from the website, and the Times’ iPad2 app.

In the second part of the study, they were randomly assigned five different chapters of a text, presented as a printed book, on the iPad2 at 12 and 18 point font, and the Kindle at 12 and 18 point font. For each format, their reading speed was calculated over a period of two minutes, and they were asked which they preferred using.

Results: Printing out the articles was associated with a slightly increased reading speed, but the real significant improvements were seen with the iPad2. All of the participants, regardless of their degree of vision loss, improved their reading speed by at least 42 words-per-minute (WPM) when looking at 18 point font on the iPad2. The same font setting on the Kindle yielded an average gain of 12 WPM.

Preference was correlated to degree of vision loss. The most severe (20/50 to 20/80) preferred the iPad2, the milder cases (20/30 to 20/40) preferred the Kindle, and those with near-perfect vision [preferred] newsprint.

Backlighting and Contrast Sensitivity

It’s important to clarify that the Kindle used in the research was the original version, which did not have a back-lighted screen. The researchers theorize that the iPad’s back-lighted screen provides greatly enhanced contrast sensitivity, a significant factor in the improved reading speed achieved by the subjects with moderate central vision loss. Reduced contrast sensitivity is common in people with low vision.

Contrast sensitivity refers to the ability to detect differences between light and dark areas; see an object as separate and distinct from its background; read faintly printed reading material; and discern shades of gray. For many individuals with low vision, increasing the contrast between an object and its background will generally make the object more visible.

As Science Daily notes, the strong word vs. background contrast provided by a back-lighted screen is a major advantage for the study subjects with low vision, since it partially corrects for reduced contrast sensitivity.

The Study Conclusions

Dr. Roth and colleagues conclude that the use of back-lighted digital tablets can be an effective intervention for people with limited central vision and moderate vision loss. According to Dr. Roth, “Our findings show that at a relatively low cost, digital tablets can improve the lives of people with vision loss and help them reconnect with the larger world.” You can view Dr. Roth discussing his innovative iPad research (with transcript) at

Additional Information

In the October 2012 issue of AccessWorld®: Technology and People Who Are Blind or Visually Impaired, the online magazine of American Foundation for the Blind (AFB), the AFB Optics Lab discusses The AFB Small Visual Display Project: Contrast Sensitivity. This ongoing project explores the needs of the human visual system regarding contrast and contrast sensitivity in small visual displays, such as those found in mobile phones and blood glucose meters.

On the SightSeeing blog from the Center for the Visually Impaired (CVI) in Atlanta, Georgia, Anisio Correia, CVI’s Vice-President for Programs, lists his Top 10 Favorite iPhone Apps. It’s well worth a read!