Virtual reality headsets are a hot topic.

Augmented reality is a type of virtual reality technology that blends what the user sees in their real surroundings with digital content generated by computer software. Using augmented reality, we can “visit” countries around the world or drive a spaceship, all from the comfort of our home.

This technology may also transform medical care, allowing a surgeon to view x-rays or chart notes while in the operation room.

How does this technology apply to eye care?

Electronic head mounted devices (HMDs) have utility for patients with vision impairment. HMDs can be designed to function like wearable CCTVs that can magnify, enhance contrast, autofocus, and zoom.

They are worn on the patient’s head like a pair of goggles or glasses and project the enhanced image in front of the patient’s eyes. HMD technology is not a new concept; it was initially created for military applications but has transitioned to industrial and entertainment purposes.

The first HMD for low vision patients, the Low Vision Enhancement System (LVES, pronounced “Elvis”), was developed over 20 years ago by a partnership between Dr. Robert Massof of Johns Hopkins University, NASA and Polaroid Corp (1), which consisted of a binocular head-mounted video display system and real-time video image processing in a system package that was battery powered.

The original HMD for patients with vision impairment, the Low Vision Enhancement System (LVES).

The LVES was shown to enhance contrast sensitivity, visual acuity, and illumination (2). However, this device was heavy and functioned a bit slow for routine use (2). Fast-forward 20+ years (past devices like the Jordy and NuVision), we’ve come into a surge of newer, faster, lighter HMDs. 

These modern HMDs advertise as an “all-in-one” device and have shown to enhance constricted visual fields (3-5), visual acuity (6), and contrast sensitivity (7).

With help of near-focus, these HMDs can make reading text accessible as well, however, they require head-hand coordination and head steadiness to stay focused on the desired print.

There are many options for low vision HMDs.

Multiple low vision HMDs are currently available, which offer zoom, magnification, contrast enhancement, and illumination options. I’ll summarize three different devices and include special features for each:

eSight Eyewear has a high-speed, high-definition camera that captures images and enhances video feeds on two OLED screens in front of the patient’s eyes. This device offers a “Bioptic Tilt” capability, which allows greater inferior peripheral vision when the person is mobile.

The device can plug into TVs, computers, tablets, and smartphones. eSight is doing a prospective multicenter study on patients with vision impairment (VA 20/60-20/400, visual field >20 degrees) to evaluate the effect of the eSight Eyewear on functional vision and vision-related quality of life.

eSight Eyewear “Bioptic tilt” position when patients are mobile

The study is ongoing, but the latest data was presented at the recent ARVO conference (May, 2017), which demonstrated that the eSight Eyewear caused significant improvement in acuity, contrast sensitivity, critical print size when reading, facial recognition as well as the patients’ self-reported ability to perform desired daily activities (Melbourne Low Vision ADL Index) and visual function (VA LV VFQ-48). Website: https://www.esighteyewear.com/

IrisVision by Visionize uses a Samsung virtual reality headset popular in video gaming. Patients wear the headset with a smartphone in it. The smartphone’s camera takes real-time images from the patients’ surroundings and magnifies them in front of their eyes.

IrisVision uses a “Bubble View” display, allowing the user to zoom in on areas or objects of interest while keeping the overall scene in context. The bubble view avoids the “telescope effect,” which occurs when you enlarge an area, causing a loss of the overall scene due to the high magnification.

The device also has a “snapshot” feature, which takes a high-resolution picture through the camera and displays it in virtual reality at whatever magnification the patient chooses and the magnified image can be navigated on a virtual IMAX screen with natural head movements.

Dr. Robert Massof wearing the IrisVision by Visionize.

Similarly, IrisVision can display videos and web content over the internet, which can also be navigated on a virtual IMAX screen. Audio comes from the phone speaker or ear buds/headphones plugged into the phone. IrisVision offers the widest field of view (70-90 degrees) and can also adjust interpupillary distance. Website: http://www.visionizellc.com/

 

NuEyes Easy uniquely features voice activation to control and change settings. It has optical character recognition (text-to-speech) capabilities, which means it can scan printed text and read out loud.

It can also be set-up to stream TV and movies in the glasses. The next generation, NuEyes Pro, is expected to launch during the summer of 2017 and includes new features that function similar to an Android computer, including internet browsing, Email, and social media applications. Website: https://nueyes.com/

Reading a book with the NuEyes Easy

HMDs represent a promising class of technologies for a growing population of patients who have the need for vision enhancement. They may offer visual aid for certain visual tasks that are not adequately addressed by existing treatment options.

HMDs do not replace orientation and mobility instructors, occupational or rehabilitation therapists, but may be a helpful tool during the vision rehabilitation process.

 

References

  1. Massof RW. Low vision enhancement: vision for the future. Eyecare Technol 1994;4(1):32-35.
  2. Culham LE, Chabra A, Rubin GS. Clinical performance of electronic, head-mounted, low-vision devices. Ophthalmic Physiol Opt 2004;24(4):281-290.
  3. Trese MGJ, Khan NW, Branham K, Conroy EB, Moroi SE. Expansion of severely constricted visual field using Google Glass.Ophthalmic Surg Lasers Imaging Retina 2016;47(5)”486-489.
  4. Bowers AR, Luo G, Rensing NM, Peli E. Evaluation of a prototype Minified Augmented-View device for patients with impaired night vision. Ophthalmic Physiol Opt 2004;24(4):296-312.
  5. Luo G, Peli E. Use of an augmented-vision device for visual search by patients with tunnel vision. Invest Ophthalmol Vis Sci 2006;47(9):4152-4159.
  6. Pelaez-Coca MD, Vargas-Martin F, Mota S, Diaz J, Ros-Vidal E. A versatile optoelectric aid for low vision patients. Ophthalmic Physiol Opt 2009;29(5):565-572.
  7. Hwang AD, Peli. An augmented-reality edge enhancement application for Google Glass. Optom Vis Sci 2014;91(8):1021-1030.