Quality of vision is initially determined by proper functionality of the eyes. In most cases, when the visual input is normal or corrected to normal, the achieved visual perception is intact. However, in some cases, a deficient visual input may be overcome by enhanced visual processing in the brain, or, conversely, abnormal processing in the brain may impair visual perception despite a perfect visual input. GlassesOff technology allows one to: (1) take advantage of the brain’s capability to compensate for input deficiency, (2) address the imperfections of the brain’s part of the equation in order to improve vision, and (3) improve normal vision to achieve enhanced performance. The GlassesOff application for near vision improvement by exercising the brain’s image processing function, currently available in Apple’s App Store, is the first of an expected suite of vision-improvement solutions based on perceptual learning methodologies.
GlassesOff SCIENCE
Our technology is based on the brain’s neuroplasticity, or the ability to alter perception, usually as a result of experience. The adult visual system is capable of substantial changes in sensitivity following visual stimulation,1,2 deprivation,3,4 and even abnormal development, as in amblyopia.5,6 During the past 2 decades, there have been numerous reports describing the surprising effects of long-term sensitivity improvement with some basic visual tasks as a result of training.7 This phenomenon, eventually named perceptual learning, allows generalization of training gains across stimuli and tasks.
GAINS IN PRESBYOPIA
Recently, we established the efficacy of the methodology used by GlassesOff in a study on presbyopes, supervised by Dennis Levi, OD, PhD, of Berkeley Optometry, University of California, Berkeley (UC Berkeley).8 The results unequivocally show that perceptual learning improves visual acuity and contrast sensitivity in presbyopes and, on average, results in performance levels similar to the young control group. After training with GlassesOff two to three times per week over a period of 2 to 4 months, visual acuity had improved by 2.6 ETDRS chart lines (improvement of above 80%), equivalent to an effective reduction in the eye age of ~8.6 years, consistent with the results found in our earlier studies.9,10 Contrast detection thresholds reached the levels of the young control group. Moreover, these results have shown, for the first time, that training transferred to an improvement of suprathreshold contrast discrimination without direct training on a contrast discrimination task. Further, all patients whose near vision abilities did not allow them to read standard newspaper-sized fonts without reading glasses were able to read freely following GlassesOff use. Finally, the average reading speed increased by 17 words per minute, saving about 9 minutes when reading a 2,000-word article at a minimal font size.
This study was the first to conclusively show that near vision improvement is not caused by improved optical performance of the eye. In collaboration with Clifton Schor, OD, PhD, of UC Berkeley, we found that precise objective measurements of accommodative power, pupil size, and depth of focus showed no changes in either of these functions, indicating that changes induced by training occurred in the brain.
Because contrast is critically important in driving neural responses in the visual cortex, the consequence of a blurred input may result in weaker and slower neuronal responses in the visual cortex, leading to degraded letter identification and reduced reading abilities. A significant reduction of contrast sensitivity function is found is presbyopia, as measured by the contrast sensitivity chart. Because of the decreased input contrast in presbyopia, there is a delay in input proportion of about 50 ms, as seen in this event-related potentials recording from our lab. The amplitude of the key components, such as P1, is decreased, and its latency becomes longer. Consequently, a bottleneck is created at the early stages of cortical processing.
PERSISTENCE OF GAINS
We recently demonstrated that the benefits of GlassesOff’s technology are persistent over time, despite the expected age-related decline in near vision.11 Results were obtained from 59 patients with different levels of presbyopia, who completed the training protocol of 2 to 4 months on mobile devices (iPhone, iPod, iPad), from 40 cm, for 15 to 30 minutes per session, three times per week, and then continued with an ongoing maintenance protocol requiring only a few sessions per month. Training gains were then retested after a period of up to 6.2 years and at least 1 year (2.5 years on average) and compared with the initial measurements and the predicted deterioration with age of ~0.50 D and 2 ETDRS lines during this period. The results show that not only is there enough capability in the adult brain to overcome and/or delay the undesired effects of aging on reading abilities, but that these benefits are persistent over the long term.
THE APPLICATION
The GlassesOff mobile application, delivered through cloud-based client server architecture, automatically monitors user performance and adjusts the succeeding training sessions. The protocol consists of two components: the Basic Program and Ongoing Vision Care. The Basic Program is composed of intensive visual stimulation tasks and requires a minimum of three 12-minute sessions per week over a period of about 3 months. By the end of the program, users who pass the initial online screening process are expected to read without glasses. Ongoing Vision Care is designed to maintain the achieved reading abilities and delay further age-related deterioration and is intended to be used once every few weeks.
Screenshots of the GlassesOff app showing (1) personal vision progress, (2) program target and progress, and (3) a vision evaluation screen.
Contrast-driven neutral response is robustly affected by lateral interactions between neurons in the visual cortex. A positive effect of lateral neuronal propogation, termed facilitation, increases contrast sensitivity.
Cortical interpretation depends on the quality of the initial input. This interpretation is a complex task, evidenced by the fact that about 50% of the brain is involved in visual processing. This complexity is illustrated by these maze-like diagrams of the heirachy of the visual areas in the brain of macaque monkey.
GlassesOff’S NEXT STEPS: ATHLETES, DRIVERS, AND MORE
The gains from the GlassesOff’s perceptual learning method were found to translate to visual acuity measured using the standard optometric charts, processing speed, and reaction time.12-14 Hence, we believe that there is a potential to develop additional apps utilizing the GlassesOff technology for improving multiple visual functions, including 3-D vision, reaction time, and object detection in several areas demanding improved or outstanding visual performance. These include some of the most exciting mass-market segments, such as apps designed to improve the performance of professional and amateur athletes in various sports, drivers’ performance, and reading speed improvement in school children and adults.
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11. Polat U, Lev M, Yehezkel O, Sterkin A. Brain plasticity overcomes presbyopia: persistence over time. Paper presented at: the American Academy of Ophthalmology Annual Meeting. November 16-19, 2013; New Orleans, LA.
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13. Lev M, Ludwig K, Gilaie-Dotan S, et al. Training improves visual processing speed. 2014. Submitted for publication.
14. Yehezkel O, Sterkin A, Lev M, Polat U. Training on spatial-temporal masking improves crowding and visual acuity. 2014. Submitted for publication.
