An implementation of Bubble Magnification did not improve the video comprehension of individuals with central vision loss

Abstract

Purpose: People with central vision loss (CVL) watch television, videos and movies, but often report difficulty and have reduced video comprehension. An approach to assist viewing videos is electronic magnification of the video itself, such as Bubble Magnification. Methods: We created a Bubble Magnification technique that displayed a magnified segment around the centre of interest (COI) as determined by the gaze of participants with normal vision. The 15 participants with CVL viewed video clips shown with 2× and 3× Bubble Magnification, and unedited. We measured video comprehension and gaze coherence. Results: Video comprehension was significantly worse with both 2× (p = 0.01) and 3× Bubble Magnification (p < 0.001) than the unedited video. There was no difference in gaze coherence across conditions (p ≥ 0.58). This was unexpected because we expected a benefit in both video comprehension and gaze coherence. This initial attempt to implement the Bubble Magnification method had flaws that probably reduced its effectiveness. Conclusions: In the future, we propose alternative implementations of Bubble Magnification, such as variable magnification and bubble size. This study is a first step in the development of an intelligent-magnification approach to providing a vision rehabilitation aid to assist people with CVL.

Comparative effectiveness between two types of head-mounted magnification modes using a smartphone-based virtual display

“…In a separate multicenter prospective trial with 51 participants using a separate head-mounted display device, similar functional improvements were observed in overall visual ability, reading, and visual information tasks. 5 However, Costela et al 19 found a deterioration in performance for video comprehension using a similar virtual bioptic display for people with good vision.…”

A systematic review of extended reality (XR) for understanding and augmenting vision loss

“…Whereas VR allows for people with low vision to experience otherwise unsafe tasks in a controlled virtual environment, AR is better suited as a real-life visual accessibility aid ( Gopalakrishnan, Chouhan Suwalal, Bhaskaran, & Raman, 2020 ), as it is allows for real-time interaction with an overlay of the real and digital world (similar to a hearing aid). Augmentation studies in this category focused on a variety of tasks, ranging from reading to face recognition (e.g., Costela, Reeves, & Woods, 2021b , 2021a ; Calabrèse et al., 2018 ) and obstacle avoidance (e.g., Huang et al., 2019 ; Angelopoulos, Ameri, Mitra, & Humayun, 2019 ). Similar to the previous section, most of the studies in this category evaluated their augmentation prototype either directly on people with low vision (e.g., Calabrèse et al., 2018 ; Houston, Bowers, Peli, & Woods, 2018 ) or indirectly by using low-vision simulations with sighted participants (e.g., Hwang & Peli, 2014 ; van Rheede et al., 2015 ; Foster, Hotchkiss, Buckley, & Elliott, 2014 ).…”