About 4 million Americans currently live with low vision (best-corrected vision worse than 20/40), and the number of new cases is expected to more than double over the next 30 years.1 In my retina practice, many of the patients who struggle with low vision — and particularly, central vision loss — have age-related macular degeneration (AMD), while others have reduced vision from retinitis pigmentosa or other inherited retinal diseases, segmental vision loss from vascular occlusions, and other conditions. Currently, only about 12.4% of those with low vision nationwide are using assistive or adaptive devices; increasing that number is one of the public health goals in the federal government’s Healthy People 2030 initiative.2
One reason for the low uptake of assistive devices is that historically, there hasn’t been much to offer these patients beyond magnification. But this is changing rapidly, thanks in part to the widespread availability of smart phones, tablets, and augmented reality (AR) or virtual reality (VR) technologies. These ubiquitous devices have been game changers for people with low vision, thanks to their ability to enlarge fonts, improve contrast, and provide talk-to-text capabilities. There are many free or low-cost applications that use the phone’s camera to describe objects to the user or convert text to speech. One service, BeMyEyes, even uses video chat for volunteers to provide real-time guidance to blind and low-vision users.
Wearable Technologies
Wearable assistive technology has been available for some time to help patients read or watch TV. Devices such as VisionBuddy, eSight 4 (eSight Eyewear), Acesight (Zoomax Technology), Eye5 (Eyedaptic), and IrisVision are all glasses or headsets that provide hands-free benefits to patients. These devices primarily serve to magnify an image, increase contrast for text, zoom in or out, and may have some image processing VR capabilities. However, many see VR technology, where the user is totally ensconced in a virtual world, as problematic because it may be difficult or dangerous to move around using VR glasses.
Increasingly, though, we are seeing the incorporation of augmented reality (AR) and artificial intelligence (AI) into low-vision assistive devices. A new assistive AR/extended reality (XR) device in development, OcuLenz (Ocutrx Technologies), goes beyond simple magnification. The OcuLenz for AMD is an unenclosed AR system (Figure 1) with which the patient can see both the real world and virtual images displayed, so walking or moving around is not dangerous. The OcuLenz headset enhances vision by overlaying high-contrast, pixel-manipulated images, shifting from areas of nonsight to the user's remaining peripheral field of view. This approach aims to come close — short of actually replacing neural retinal tissue — to solving many of the day-to-day problems of patients with low vision.
The first time the patient wears the OcuLenz headset, they go through an automated visual field test to map out the size and location of each eye’s central defect. That information is incorporated into the software algorithms so that images from the forward-facing cameras can be spread around the scotoma to provide a full field of vision (60° horizontally x 40° vertically x 72° diagonally) to the areas that still have functional retina. Sophisticated eye tracking moves the image as the patient moves their eyes. The headset becomes the user’s phone and internet connection, with wifi and cellular connection capabilities.
Anecdotally, I have found that patients who have tested this device rapidly adapt to ignore the dark central spot and maintain their focus on the peripheral image. Even my older AMD patients adapt surprisingly well, quickly grasping how the device can enhance their lifestyle and improve their functional abilities — even if they don’t fully understand how the underlying technology works.
Another wearable technology is the MyEye Pro (OrCam), which allows users to navigate their environment in an interactive way. Attached to a pair of spectacles, MyEye Pro (Figure 2) uses voice-activated, intuitive AI to audibly describe what’s in a room, respond to open-ended queries for specific information, and help the user recognize faces. The device can also summarize text from books and screens, scan barcodes, and verify monetary amounts. The same company also makes a hand-held reading device, the AI-driven Read 3, which allows individuals with mild to moderate vision loss to read, magnify, summarize, and search printed and digital text.
We haven’t yet even come close to understanding the potential impact of AI on daily life for the vision impaired. The image processing and threat awareness capabilities that automobile companies are developing for self-driving vehicles, for example, can also help those with low vision successfully navigate their environment.
Limitations of AI and AR technology right now include battery power and size as well as cost. As we have seen with consumer technology, batteries will continue to improve, enabling longer-lasting, smaller, and lighter wearable devices. Technology also tends to become more affordable over time, but it remains the case that assistive devices and tools typically aren’t covered by Medicare or other insurance, putting them financially out of reach for some patients.
A Good Time to Learn More
Most retina specialists are aware of low-vision aids generally, but with the current explosion of technology, this is a good time to become more educated about new assistive devices and to connect with a good low-vision specialist for referrals. Low-vision optometrists can help patients with very moderate to very severe vision loss increase their functioning, and they often have technology for patients to try before they buy. The International Academy of Low Vision Specialists is one source for referral contacts and more information about assistive technology.
Although retina specialists are often focused on specific metrics, like visual acuity or field loss, for patients, it is worth remembering what these nonmedical aids can deliver: the ability to continue working, to maintain independence by being able to shop and cook, and the chance to see their loved ones’ faces. I find that even elderly patients who are already in a nursing home benefit from regaining the ability to recognize faces in a social setting. It can make them feel less isolated, less anxious, and more willing to engage with others. This is a promising time for patients with low vision.
References
- Chan T, Friedman DS, Bradley C, Massof R. Estimates of incidence and prevalence of visual impairment, low vision, and blindness in the United States. JAMA Ophthalmol. 2018;136(1):12-19. doi:10.1001/jamaophthalmol.2017.4655
- Office of Disease Prevention and Health Promotion, US Department of Health and Human Services. Healthy People 2030. Accessed April 11, 2024. https://health.gov/healthypeople/objectives-and-data/browse-objectives/sensory-or-communication-disorders/increase-use-assistive-and-adaptive-devices-people-vision-loss-v-09
