Video Games Improve 'Lazy Eye' in Adults, Study Suggests

Yael Waknine

September 08, 2011

September 8, 2011 — Adults with amblyopia can achieve substantial improvements in visual acuity by playing video games for 40 hours, suggest the results of a pilot study published online August 30 in PLoS Biology.

"This study is the first to show that video game play is useful for improving blurred vision in adults with amblyopia," said study lead author Roger Li, OD, PhD, research optometrist at the School of Optometry and the Helen Wills Neuroscience Institute at University of California–Berkeley, in a university news release. "I was very surprised by this finding; I didn't expect to see this type of improvement."

No studies have shown similar benefits for individuals with normal vision.

Amblyopia, also known as "lazy eye," is a brain disorder that causes reduced vision in 1 eye. It affects 2% to 3% of American children and represents the most frequent cause of permanent 1-eye visual impairment among young and middle-age adults. Although pediatric options include occlusion therapy and use of atropine drops to blur vision in the stronger eye, no treatments are currently available for adults.

"There is general impression among eye doctors that once a child reaches a certain age (usually around age 12 [years]), treating amblyopia by patching the good eye will not be effective anymore," Stuart R. Dankner, MD, FAAP, FACS, told Medscape Medical News in an interview. "This study reinforces that it's probably never too late to attempt to treat amblyopia, although the success rate is much less in adults who are treated for amblyopia as compared to treating in early childhood."

Dr. Dankner is a pediatric ophthalmologist in private practice and an assistant clinical professor at John Hopkins Medical Institution in Baltimore, Maryland. He also serves as a clinical correspondent for the American Academy of Ophthalmology. He was not involved in the study.

Study Findings

In a study supported by the National Eye Institute, investigators placed an eye patch over the good eye in 20 adults aged 15 to 61 years and randomly assigned them to 1 of 3 intervention groups. In 2 groups, patients used the amblyopic eye to play either an action video game requiring target shooting (Medal of Honor: Pacific Assault, Electronic Arts, Inc; n = 10) or a nonaction game that required users to construct something (SimCity Societies, Electronic Arts, Inc; n = 3). The third group received conventional occlusion therapy (n = 7). Video games were played for a total of 40 hours, 2 hours at a time, over the course of a month.

Results showed that 40 hours of video play (either game) yielded a 30% improvement in visual acuity, representing a mean improvement of 1.5 lines on a standard LogMar optometric chart. In comparison, it can take 120 hours of occlusion therapy to achieve a 1-line improvement on the letter chart in amblyopic children, investigators noted in the news release.

A comparison with the control group confirmed that the benefit was specific to video game playing and not occlusion therapy: No visual improvements were noted during a 20-hour course of normal daily activities such as watching television, reading books, and surfing the Internet. After playing video games for 40 hours, these patients showed similar improvement as the other study participants.

Furthermore, patients who started off playing the nonaction video game continued to improve after playing the action game for an additional 40 hours. "It is not clear, yet, when vision improvement might plateau," Dr. Li noted.

No differences were observed between patients with strabismic amblyopia (n =10), anisometropic amblyopia (n = 6), both conditions (n = 3), or amblyopia caused by cataract (n = 1).

The experiment was initially designed to see whether playing a video game could improve "visual attention" in patients with amblyopia, Dr. Li told Medscape Medical News in an interview.

"Actually, I didn't expect to see any improvements in spatial vision or 'letter' acuity in the beginning," Dr. Li noted. "Very surprisingly, besides enhanced visual attention, all participants showed a remarkable improvement in amblyopic visual acuity following a short period of video game play."

Other findings included a 37% improvement in spatial attention and a 16% increase in positional acuity. Anisometropic patients achieved a 54% improvement in 3-dimenstional depth perception, and some even regained normal stereoacuity and were pronounced "cured" in that aspect of their vision.

Clinical Implications

Dr. Li cautioned that research on video game therapy is still in its early stages.

"It is very important that patients should not try self-treating amblyopia," Dr. Li told Medscape Medical News. "Patients should consult their eye doctors. Response to treatment must be closely monitored to avoid possible unwanted conditions such as double vision, reverse amblyopia, eye strain, and headache, etc."

"Video game therapy or other similar methods may be promising but is not an accepted medical protocol for treating amblyopia in older patients," Dr. Dankner concurred. "More critical research involving many more patients in more well-controlled studies needs to be performed before any recommendation can be made about whether this is going to be an effective therapy or not."

If efficacy is confirmed in adults, additional studies need to be performed in amblyopic children to determine whether long-term exposure to video stimuli is safe, because health risks such as seizures have been implicated in some vulnerable children.

Perhaps a better approach would be a new therapeutic model in which visual stimuli are created to stimulate specific areas in the brain that cause amblyopia.

"When we know what suppressed areas in the brain cause amblyopia, and then formulate more specific visual stimuli that will activate these areas, then amblyopia treatment should be more effective," Dr. Dankner added.

Still, findings from this pilot study may represent the potential for brain cells to be stimulated, and perhaps even regenerated, later in life.

According to the news release, the investigators have obtained a 3-year, $1.7 million National Eye Institute grant to conduct a randomized trial comparing video game and occlusion therapy for amblyopia in children and adults. The study will be conducted in collaboration with researchers at the University of Rochester and the Rochester Institute of Technology in New York and will employ customized video games that are nonviolent and child-friendly.

The study was funded by the National Eye Institute. Dr. Li and Dr. Dankner have disclosed no relevant financial relationships.

PLoS Biol. Published online August 30, 2011. Full text