Susan Barry’s recent book, Fixing My Gaze , is a vivid narrative of her life with a small but intrusive disability—strabismus (“crossed eyes”)—with its common effect of poor depth perception. Barry recounts the events of her infancy, when her strabismus developed; the operations that cosmetically corrected the condition without correcting her vision; her awkward school days; difficulty with driving and other tasks requiring judgment of depth; and so on, until a behavioral treatment, she says, transformed her life. She describes her experiences vividly, even poetically, and intersperses scientific discussions with anecdotes that serve as the “spoonful of sugar that helps the medicine go down.” The book reads well enough to have been selected as a Library Journal Best Sci-Tech Book of 2009. But Barry seems to have forgotten that anecdotes do not provide sufficient evidence to make serious claims about therapies.
Regrettably, this rather charming and informative book serves as an extended advertisement for “developmental optometry” (“orthoptics),” a program that is claimed to correct some visual problems through eye exercises that increase control of convergence and divergence—the coordinated eye movements that are needed to see things in focus. She properly excludes from consideration self-help orthoptic methods like the Bates method, which is critiqued elsewhere on Quackwatch . However, she advocates the Brock method, which appears to me to have as little plausibility and as weak an evidence base as the rest. In addition, Barry attributes her improvement to “rewiring” of the brain and, like many others who resort to this inapt metaphor, suggests that the high levels of juvenile brain adaptability persist throughout life. It’s possible that they do, but Barry’s examples may be more parsimoniously explained by the less dramatic brain changes we call “learning.”
Textbooks on visual perception suggest plausible ways in which eye exercises that improve eye coordination might help depth perception without “rewiring” anything. However, the definitive way to evaluate orthoptics is through systematic tests of perception before and after treatments by developmental optometrists. Barry’s book almost completely excludes these data.
Most serious research on aspects of vision therapy has concentrated on its role in treating amblyopia (lazy eye). A Cochrane review of two randomized controlled trials showed no clear evidence of benefit from the type of visual activity used in vision therapy protocols . A study that used retrospective comparisons to case records reported that eye exercises did not appear to reduce symptoms in patients with esophoria, a mild version of the “in-turned” eye position Susan Barry had to cope with . A randomized controlled study using several placebo and other treatments reported significant improvement using specific vision therapy methods, but it excluded from the study patients with constant strabimus or a history of strabismus surgeryâ€”categories into which Susan Barry would fall . None of these high-quality investigations appears to have used the Brock protocol that Barry advocates.
Both CIGNA HealthCare and Aetna have reviewed the literature and consider vision therapy experimental and investigational. CIGNA covers it only for when used before surgery for acquired esotropia, a condition in which the eye tends to turn inward as a result of trauma or disease . Aetna covers several uses but excludes anomalous retinal correspondence, one of Susan Barry’s problems .
One cannot argue with Barry’s subjective experiences or her sense that improved eye coordination opened a new world of visual excitement and visually-related skills. Whether others can benefit equally from what she did remains questionable, however, and it is regrettable that her book, while filled with scientific facts, did not place them in proper perspective.
- Barry S. Fixing My Gaze: A Scientist’s Journey Into Seeing in Three Dimensions. New York: Basic Books, 2009.
- Worrall RS and others. Eye-related quackery. Quackwatch,
- Shotton K, Elliott S. Interventions for strabismic amblyopia. Cochrane Database of Systematic Reviews, Apr 16;(2):CD006461, 2008.
- Aziz S and others. Are orthoptic exercises an effective treatment for convergence and fusional deficiencies? Strabismus 14:183-189, 2006.
- Convergency Insufficiency Treatment Trial (CITT) Study Group. The Convergence Insufficiency Treatment Trial: Design, methods, and baseline data. Ophthalmic Epidemiology 15:24-36, 2008.
- CIGNA Medical Coverage Policy: Vision therapy/orthoptics. Dec 15, 2008.
- Aetna Clinical Policy Bulletin 0489: Vision therapy. Dec 18, 2009.
Dr, Mercer is a developmental psychoilogist whose early training was in perception. She has been professor of psychology at Richard Stockton College in Pomona, New Jersey since 1981. She has a special interest in parent-infant relationships and writes the Child Myths blog for Psychology Today.