Assistive technology is commonly defined as any item, piece of equipment, or product system whether acquired commercially off the shelf, modified, or customized that is used to increase, maintain, or improve the functional capabilities of people with disabilities. For people with low vision, assistive technology can take many forms. It certainly feels like we are at a point in time where the rate of change and the number of new developments in assistive technology are almost mind-boggling. There is enormous potential for harnessing widely available consumer technology for use in low-vision rehabilitation, and new applications for smartphones and tablets meant to help people with low vision are constantly being introduced. Artificial intelligence is being applied to the challenges of low vision, three-dimensional printing is making new assistive devices possible, and some of the world's biggest companies are making real commitments to the development of assistive technology for people with vision impairment. Of course, these are only a few of the ways in which technological development is having an effect on the lives of people with low vision.
And yet, amid the excitement of new technological breakthroughs and possibilities, it is not difficult to recognize some significant challenges. For instance, how do we know which of these technologies are actually useful to people with low vision and which are overpriced gadgets that do not particularly solve any real problems and are unlikely to be widely adopted? How does the low vision rehabilitation clinician keep current on the state of new developments or know which assistive technology is best for a particular patient? How do we train people with vision impairment to use all of these exciting new assistive technologies?
Well, the good news is that there are a number of great resources available. One example is the American Foundation for the Blind's AccessWorld Magazine, which has been providing reviews and news on technology for low vision for decades. Another favorite of mine is “The Blind Life,” a YouTube channel featuring Sam Seavey's funny and insightful takes on living with low vision and honest informative reviews of new assistive technology. And, of course, the optometric and vision science communities are hard at work generating evidence that can help patients, clinicians, and developers of new technology sort it all out. This feature issue of Optometry and Vision Science puts that work on display and shows researchers from varied backgrounds attacking the problems of assistive technology development and use from all sides.
It is worth noting that, although we are clearly living in an exciting time for assistive technology development, many of today's breakthroughs are the result of years of work and dedication on the part of researchers, and it is important to consider the historical context when examining new devices. One well-publicized assistive technology development that many people in the low vision community will remember was the introduction of the first head-mounted video magnification system, the Low Vision Enhancement System,1 20 years ago. In fact, the effectiveness of the Low Vision Enhancement System for reading was examined in Optometry and Vision Science shortly after its release.2 In this issue's feature article, Deemer and colleagues3 trace the history of head-mounted video magnification systems, beginning with the Low Vision Enhancement System and continuing to the wide variety available today, and provide guidance on what challenges remain in making these systems more useful for people with low vision. Wittich and colleagues4 evaluate the effect of one current iteration of this device type (eSight) on visual function. About 17 years ago, in a low vision feature issue of Optometry and Vision Science, Eli Peli5 described the development of new devices that used vision multiplexing for rehabilitation. Reinforcing the idea that new advances often occur as a result of building on past work, the current feature issue contains an article by Jung and Peli6 that describes the design and evaluation of a new multiplexing device that provides visual field expansion for acquired monocular vision. Also, in this issue, these authors provide evidence that full-field prisms, which have a history of being prescribed for field expansion, do not, in fact, provide any useful expansion of the visual field.7 These studies illustrate both the ways in which technological advances can allow for the creation of new solutions and the need for persistence and rigorous evaluation in the development of assistive technology. This feature issue demonstrates the progress that has been made and likely contains seeds for the advances of the coming decades.
Smartphones and tablets are now ubiquitous, and they are increasingly being used in a low vision rehabilitation capacity. This issue contains multiple articles evaluating the usefulness of these devices for reading with low vision,8,9 as well as others that feature novel observations about the way in which these devices are used by people with low vision that could guide future development.10,11 Hayhoe12 provides a unique perspective in a review of the literature on mobile devices for learners with vision impairment, concluding that researchers and technology developers often seem to lack an effective way to communicate between disciplines and often fail to fully understand the nature of learners with low vision, resulting in slowed progress in the development of effective solutions. In addition, Bittner et al. assess the feasibility of a novel telemedicine approach for low vision rehabilitation that uses tablets in patients' homes.13
Also evident in this feature issue are the varied activities for which modern assistive technology can potentially be of use. Calabrèse and colleagues present an aid that shows promise for improving face recognition in people with AMD.14 Satgunam et al.15 show how three-dimensional printing can be used to produce toys that could help children learn Braille, and Bowers et al. use a novel driving simulation paradigm to investigate hazard detection in bioptic drivers.16 There is clearly a great deal of interest in the development of new technologies to help people navigate in their environments more effectively. Multiple unique approaches to achieving safe mobility are presented using an array of different technologies including augmented reality in head-mounted displays,17 peripheral prisms,18 wearable cameras with vibro-tactile wristbands,19 and other sensory substitution devices.20,21
Another theme that comes through in this feature issue is the need to assess the perspectives and behaviors of the patients for whom this assistive technology is made. Whether prescribed assistive devices are actually used is an important indicator of their value. Those who have followed developments in technology for low vision will have no trouble naming seemingly exciting devices that were not widely adopted and are no longer available. In this vein, Ross and colleagues22 present findings on the rate at which people use prescribed low vision aids, and Bittner and colleagues investigate the feasibility of using Bluetooth beacons to monitor the frequency of use of prescribed magnifiers.23
Technology can also play a meaningful role in improving our ability to assess people with vision impairment, and the insights gained can be expected to improve rehabilitation strategies in the future. Bernard and Chung use a scanning laser ophthalmoscope to demonstrate that visual acuity at the preferred retinal locus is not always the best.24 Wittich and colleagues evaluate a device that is meant to help clinicians and patients determine ideal lighting settings and pick appropriate light bulbs.25 Bittner et al. assess the activity and sleep patterns of people with retinitis pigmentosa using an accelerometer worn on the wrist.26 Laby presents a case report suggesting that the technology commonly used in sports vision assessment and training may have a role for improving coordination and object tracking in people with low vision.27
Finally, it is important to remember that all of the potential benefits of assistive technology for low vision require that the people who need it have access. In fact, the World Health Organization estimates that one billion people globally need at least one assistive device, but about only 1 in 10 people in need actually has access to assistive technology.28 In a clinical perspective in this feature issue, du Toit and colleagues29 elaborate on the challenges of providing access to assistive technology for people with low vision and suggest specific strategies for eye care providers to improve the situation. The progress we as a community make in the development of new assistive technology must be realized in concurrence with progress in expanding access.
The response from authors to our call for submissions for this feature issue was tremendous, and this is reflected in the size of the issue. It must be noted that the production of such a large feature issue requires a great deal of hard work on the part of editors and reviewers. I am tremendously grateful to the brilliant and hardworking guest editor team—Gordon Legge, Susana Chung, Lei Liu, and Ava Bittner—for their stellar efforts in moving submissions through the review process as well as for their valuable insights and judgment. In addition, we are all very appreciative of the work performed by the many reviewers who gave of their time and shared their expertise in reviewing the articles presented here.
Bradley Dougherty, OD, PHD, FAAO
1. Massof RW, Rickman DL. Obstacles Encountered in the Development of the Low Vision Enhancement System. Optom Vis Sci 1992;69:32–41.
2. Ortiz A, Chung ST, Legge GE, et al. Reading with a Head-mounted Video Magnifier. Optom Vis Sci 1999;76:755–63.
3. Deemer AD, Bradley CK, Ross NC, et al. Low Vision Enhancement with Head-mounted Video Display Systems: Are We There Yet? Optom Vis Sci 2018;95:694–703.
4. Wittich W, Lorenzini MC, Markowitz SN, et al. The Effect of a Head-mounted Low Vision Device on Visual Function. Optom Vis Sci 2018;95:774–84.
5. Peli E. Vision Multiplexing: An Engineering Approach to Vision Rehabilitation Device Development. Optom Vis Sci 2001;78:304–15.
6. Jung JH, Peli E. Field Expansion for Acquired Monocular Vision Using a Multiplexing Prism. Optom Vis Sci 2018;95:814–28.
7. Jung JH, Peli E. No Useful Field Expansion with Full-field Prisms. Optom Vis Sci 2018;95:805–13.
8. Wittich W, Jarry J, Morrice E, et al. Effectiveness of the Apple iPad as a Spot-reading Magnifier. Optom Vis Sci 2018;95:704–10.
9. Gothwal VK, Thomas R, Crossland M, et al. Randomized Trial of Tablet Computers for Education and Learning in Children and Young People with Low Vision. Optom Vis Sci 2018;95:873–82.
10. Granquist C, Wu YH, Gage R, et al. How People with Low Vision Achieve Magnification in Digital Reading. Optom Vis Sci 2018;95:711–9.
11. Tennison JL, Carril ZS, Giudice NA, et al. Comparing Haptic Pattern Matching on Tablets and Phones: Large Screens Are Not Necessarily Better. Optom Vis Sci 2018;95:720–6.
12. Hayhoe S. Epistemological Trends in the Literature on Mobile Devices, Mobile Learning, and Learners with Visual Impairments. Optom Vis Sci 2018;95:889–97.
13. Bittner AK, Yoshinaga P, Bowers A, et al. Feasibility of Telerehabilitation for Low Vision: Satisfaction Ratings by Providers and Patients. Optom Vis Sci 2018;95:865–72.
14. Calabrèse A, Aguilar C, Faure G, et al. A Vision Enhancement System to Improve Face Recognition with Central Vision Loss. Optom Vis Sci 2018;95:738–46.
15. Jain T, Christy B, Das AV, et al. Fittle: A Novel Braille Toy. Optom Vis Sci 2018;95:902–7.
16. Bowers AR, Bronstad PM, Spano LP, et al. Evaluation of a Paradigm to Investigate Detection of Road Hazards when Using a Bioptic Telescope. Optom Vis Sci 2018;95:785–94.
17. Kinateder M, Gualtieri J, Dunn MJ, et al. Using an Augmented Reality Device as a Distance-based Vision Aid—Promise and Limitations. Optom Vis Sci 2018;95:727–37.
18. Houston KE, Bowers AR, Peli E, et al. Peripheral Prisms Improve Obstacle Detection during Simulated Walking for Patients with Left Hemispatial Neglect and Hemianopia. Optom Vis Sci 2018;95:795–804.
19. Pundlik S, Tomasi M, Moharrer M, et al. Preliminary Evaluation of a Wearable Camera-based Collision Warning Device for Blind Individuals. Optom Vis Sci 2018;95:747–56.
20. Hoffmann R, Spagnol S, Kristjánsson Á, et al. Evaluation of an Audio-haptic Sensory Substitution Device for Enhancing Spatial Awareness for the Visually Impaired. Optom Vis Sci 2018;95:757–65.
21. Grant P, Maeng M, Arango T, et al. Performance of Real-world Functional Tasks Using an Updated Oral Electronic Vision Device in Persons Blinded by Trauma. Optom Vis Sci 2018;95:766–73.
22. Gobeille MR, Malkin AG, Jamara R, et al. Utilization and Abandonment of Low Vision Devices Prescribed on a Mobile Clinic. Optom Vis Sci 2018;95:859–64.
23. Bittner AK, Jacobson AJ, Khan R. Feasibility of Using Bluetooth Low Energy Beacon Sensors to Detect Magnifier Usage by Low Vision Patients. Optom Vis Sci 2018;95:844–51.
24. Bernard JB, Chung STL. Visual Acuity Is Not the Best at the Preferred Retinal Locus in People with Macular Disease. Optom Vis Sci 2018;95:829–36.
25. Wittich W, St. Amour L, Jarry J, et al. Test-retest Variability of a Standardized Low Vision Lighting Assessment. Optom Vis Sci 2018;95:852–8.
26. Bittner AK, Haythornthwaite JA, Patel C, et al. Subjective and Objective Measures of Daytime Activity and Sleep Disturbance in Retinitis Pigmentosa. Optom Vis Sci 2018;95:837–43.
27. Laby DM. Case Report: Use of Sports and Performance Vision Training to Benefit a Low Vision Patient's Function. Optom Vis Sci 2018;95:898–901.
29. du Toit R, Keeffe J, Jackson J, et al. A Global Public Health Perspective: Facilitating Access to Assistive Technology. Optom Vis Sci 2018;95:883–8.