If you’re the parent of a child who’s having trouble learning or behaving in school, you quickly find yourself confronted with a series of difficult choices.

You can do nothing — and watch your child flounder while teachers register their disapproval. Or you can get help, which generally means, first, an expensive and time-consuming evaluation, then more visits with more specialists, intensive tutoring, therapies, perhaps, or, as is often the case with attention issues, drugs.

For many parents — particularly the sorts of parents who are skeptical of mainstream medicine and of the intentions of what one mother once described to me as “the learning-disability industrial complex” — this experience is an exercise in frustration and alienation.

These parents often don’t trust the mental-health professionals who usually treat children with “issues,” as we euphemistically tend to refer to problems like learning disabilities, attention-deficit hyperactivity disorder, autismor other developmental difficulties. They find offensive the prospect of having a child “labeled” when his or her development doesn’t correspond to what seem like random, overly restrictive norms. They find the notion of putting children on psychotropic medication frightening and unacceptable. They want to find concrete causes for their children’s diffuse, often difficult-to-understand problems and, ideally, to find cures. They want their children to achieve, and they’re dissatisfied with what they feel are the palliative half-measures offered by pediatricians,psychiatrists, psychologists and learning specialists.

That’s why some of these parents end up seeking the services of people like Stanley A. Appelbaum.

Appelbaum is a behavioral optometrist, part of a growing subspecialty of optometry that takes the traditional practice beyond its usual focus on eye health and eyesight. Through a practice referred to as vision therapy — a combination of in-office and at-home eye exercises — many of these optometrists claim they can offer significant help for problems that go far beyond the headaches, neck aches, eyestrain and poor posture typically associated with vision problems. According to Visionandlearning.org, a behavioral-optometry Web site, vision therapy can be used to treat reading problems, learning problems, spelling problems, attention problems, hyperactivity, coordination problems; it can also treat a child who experiences “trouble in sports,” who “frustrates easily,” displays “poor motivation,” and “does not work well on his own” — virtually anything that presents as an “impaired potential for achievement,” to borrow a phrase from the prominent late optometrist Martin H. Birnbaum. They can do this because for behavioral optometrists, vision isn’t just about eyes or eyesight but is also something more holistic — “how eyes work together and move together and process information and store information and do something with the information,” as Appelbaum puts it. Vision therapists caution that they cannot cure “real” cases of A.D.H.D.,dyslexia or other learning disabilities. But since they say that such disorders in children are frequently misdiagnosed, the distinction often is moot.

To the uninitiated, vision therapy is a funny-looking endeavor. Practitioners’ offices are equipped with picture-viewing stereoscopes that look like something from the Victorian era. Some practitioners use a Visagraph — black goggles hooked up with infrared sensors — to measure and track children’s eye movements while reading and to test their fluency and comprehension. Depending on the practice, you may see children standing in hula hoops, dodging balls suspended from strings, looking through prisms that give them double vision and then trying to fuse the image, playing Wii-like games for balance and “visual thinking” or pointing to bright spots blinking on a light box for hand-eye coordination.

When I visited Appelbaum in January, I watched as a boy named Brian Dennis sat on a stool wearing prism glasses and struggling to see straight as he faced a spinning board covered with red and green lines and black squares. As the board turned and a metronome ticked, he worked to follow the shapes as they swiveled, keeping them clear, single and distinct, one eye at a time. Some young patients, Appelbaum noted with a laugh, leave their therapy sessions only to vomit on his waiting-room floor, which is why his entryway is now uncarpeted.

On the day that we met in that bare-floored vestibule, Appelbaum spoke animatedly with Brian’s mother, Francesca Dennis, who works in human resources and is from Silver Spring, Md. An affable man, Applelbaum has an enthusiasm for vision therapy that is boundless and infectious. As a child, he suffered from chronic headaches and hated to read. Then in optometry school, in the 1970s, he found out he had convergence insufficiency — a condition characterized by eyes that don’t turn in together, or converge, well for close work like reading — and was treated with eye exercises. His headaches disappeared, and his life was changed. “I went from a reluctant reader to this voracious, active reader,” he says.

Brian began vision therapy because he, too, hated to read. He was doing poorly in school, struggling to stay focused in class, and his teachers started suggesting he had attention-deficit disorder. His school, a private religious school, began intimating that he might have to leave.

“He was becoming more and more frustrated,” his mother recalled.

A psychologist diagnosed anxiety, saying that a toxic school environment was driving Brian to distraction.

But Dennis suspected another cause of her son’s difficulties. He was born walleyed, with one eye that visibly turned out. And although the condition largely disappeared over the years, and though a pediatric ophthalmologist who had followed Brian since infancy said the boy had perfectly normal vision, Dennis was sure that something was being overlooked. “I just kept thinking,” she told me in the waiting room, “he wasn’t paying attention in school because of that eye.”

Appelbaum agreed. He prescribed a range of exercises to get Brian’s eyes to stay straight and work together. He also gave Brian a pair of extremely low-power glasses to help reduce his “visual stress” — the fatigue he says accompanies trying to work with improperly aligned eyes.

Brian did the exercises and, at home at least, wore the glasses. And after four months, his mother said, he “just blossomed.” He became happier in school. He improved in sports. “Now he just has so much confidence,” Dennis told Appelbaum, as she waited for Brian to finish a therapy session.

Appelbaum then told Dennis about Larry Fitzgerald, the Arizona Cardinals wide receiver, who started life appearing to be a not-particularly-gifted athlete. He didn’t like reading. He didn’t do well in school. But then he got vision therapy — help that, Fitzgerald has said publicly in recent years, changed everything. And he went on to become a star.

This is one of Appelbaum’s favorite stories.

“This is gonna be Brian,” he said.

“Whatever it costs, whatever we have to do,” Dennis declared. She and her husband were committed, she said.

The ground-floor hallway of Appelbaum’s homey practice is hung with framed statements from ecstatic parents and former patients who say their headaches, reading problems,clumsiness, low self-esteem and school misery evaporated once they began to do vision therapy.

Appelbaum keeps scores of additional happy stories in a folder. There is one from a family in San Francisco who flew cross-country one summer and stayed three weeks so that their third-grade son could do two hours of vision therapy a day. Subsequently, they write, he went up two grade levels in reading and started to play sports. There is also a note from the family of a girl whose struggles in school were so terrible that her mother quit her job in order to have the time and energy to help with homework. After vision therapy, she reads without help, is first-chair violin in the school orchestra and is now volunteering to work with a blind child.

These glowing reports are echoed on the Internet, where sites like the Optometrists Network and Parents Active for Vision Education are filled with tributes to the life-changing effects of vision therapy and tales of unfortunate encounters with mainstream medical specialists who either overlook important vision issues in children or misdiagnose them as learning disabilities, emotional problems or A.D.H.D. They refer readers to studies showing links between vision problems like convergence insufficiency and reading and attention issues.

According to a press release by the American Optometric Association, “studies indicate that 60 percent of children identified as ‘problem learners’ actually suffer from undetected vision problems and in some cases have been inaccurately diagnosed with attention-deficit disorder or attention-deficit hyperactivity disorder.” Many behavioral optometrists say that 20 to 25 percent of children overall have vision problems that can impede their ability to reach their potential. These problems commonly include: poor eye-movement control or “tracking issues,” problems with accommodation (when the eyes don’t focus well together or sustain focus at various distances), convergence insufficiency, difficulties sustaining visual attention, poor visual-motor integration (bad hand-eye coordination), weak visual form perception (the ability to reproduce and generalize shapes) and poor visual memory. The symptoms of these eye problems, the vision therapists say, commonly include getting lost on the page while reading, difficulty copying from the blackboard or from one page to another, skipping or omitting words while reading, an avoidance of close work, difficulty in remaining focused, poor handwriting and sports performance. With vision therapy, in most cases, these problems can be fixed, they say. And through more holistic, more natural, more humanistic methods than those offered by mainstream medicine.

Or, as Appelbaum puts it: “There are a lot of doctors and therapists who have a vested interest in teaching the child how to deal with their problem. Then there are people like me . . . who want to get rid of the root of the problem.”

The claims that many make for vision therapy are controversial. In fact, vision therapy is a practice that many doctors say lacks a solid grounding in good science. “It has no validity,” says Marshall Keys, a Rockville, Md., pediatric and adolescent ophthalmologist who is an outspoken critic of vision therapy.

Pediatricians do not generally refer patients to vision therapy. Ask about vision therapy at the National Institute of Mental Health (the branch of the National Institutes of Health that includes learning disabilities and A.D.H.D. in its purview), and they draw a blank. The same is true at the National Institutes of Health’s National Center for Complementary and Alternative Medicine, where you might assume vision therapy would be a subject of interest. Query the National Eye Institute, the branch of the N.I.H. that conducts vision research and you get one study — one single randomized, placebo-controlled “gold standard” study — that recommends in-office vision therapy for the treatment of convergence insufficiency, the condition for which Appelbaum was so successfully treated back in optometry school. Beyond that, you get the sense that doctors speaking in an official capacity don’t much like to offend their colleagues. “The kind of proof we look for in terms of things we want to uniformly refer to people is really at the level of science,” Brian Brooks, an investigator and the chief of the unit on pediatric, developmental and genetic ophthalmology at the National Eye Institute, told me. “The N.E.I. is here to do science — we want to encourage science. . . . That’s the area of discomfort.”

Vision therapy’s critics argue that the published research in its favor is largely anecdotal, often derived from studies in which the practitioners had a vested interest in positive results, where disorders were badly defined and therapies inconsistently practiced and during which children were usually receiving other kinds of therapy.

All of that renders the research “useless scientifically,” says Walter Fierson, a pediatric ophthalmologist in Southern California and a former chairman of the American Academy of Pediatrics’ section on ophthalmology.

Critics say that behavioral optometry rests upon some very basic misconceptions about the way the brain operates, particularly regarding the processes involved in paying attention and reading. They point out that recent advances in brain imaging have shown that most reading problems are not vision problems but instead involve glitches in language processing in the brain.

Some behaviors, they say, appear to be caused by problems with vision but really aren’t. Children with dyslexia, for example, may often lose their place while reading, but this isn’t because they have eye issues — many studies have shown that ocular coordination, movement and visual processing are normal in these children — but because they are struggling to decode letters and word combinations. Some critics do acknowledge that eye problems like convergence insufficiency and accommodation disorders can cause serious problems with reading. But they argue that behavioral optometrists grossly overdiagnose these conditions, which pediatric ophthalmologists say occur in only a small percentage of children — perhaps 1 percent of the patients he sees, says David Guyton, a professor of pediatric ophthalmology and the director of the Krieger Children’s Eye Center at the Wilmer Eye Institute, at Johns Hopkins Hospital.

“Ophthalmologists as a rule do not test for convergence insufficiency or accommodation disorders,” Appelbaum responds. “If you don’t test for a problem, you won’t see it at all.”

At base, the dispute comes down to the fact that behavioral optometrists and pediatric ophthalmologists define what constitutes a diagnosable level of problems like convergence insufficiency differently. “The two professions can’t talk to each other because their basic definitions are so different,” Guyton says.

Guyton says that many of his colleagues in ophthalmology can be too categorical in condemning vision therapy, which he says can be of real value in helping patients overcome a number of eye problems. The trouble is, he says, behavioral optometrists overstate their claims, generalizing, for example, from the evidence that vision therapy works for convergence insufficiency to validate all that they do. “You really can’t validate by association,” Guyton says.

He and other critics say, for example, that the low-power glasses that behavioral optometrists prescribe to reduce stress are so weak that they can’t actually have any effect on a child’s vision — except to make the child believe that they are helping his vision (or to please a parent who believes they are helping the child’s vision).

And A.D.H.D. specialists argue that the symptoms behavioral optometrists attribute to problems with vision (problems with “visual attention,” specifically) are primarily problems of self-regulation and executive function. It may look as if these kids are having problems with their eyes — they’ll look away from what they’re supposed to attend to; they’ll lose track of where they are while reading, or jump over words on a page — but the problem is occurring in the part of the brain that controls attention, not vision, says William Stixrud, a neuropsychologist in Washington. The behavioral optometrists, Stixrud notes, often confuse association and causation. These kids “do have problems with things like visual memory, but that’s because those parts of the brain that do that also control attention.” Stixrud adds that he does refer some children to vision therapy, but only if they have “adequate reading skills but it’s uncomfortable for them to read, they have headaches or words bounce around on the page.”

It isn’t just ophthalmologists, arguably the natural business rivals of optometrists, or learning or attention specialists (also competitors for clients), who dispute many of the claims of behavioral optometry. Eager to assess the validity of the practices of a growing number of their colleagues, the U.K. College of Optometrists, an association of optometrists, commissioned major reviews of the literature on vision therapy in 2000 and 2008. The studies came out in favor of in-office exercises for convergence insufficiency and also found there was valid research to indicate that vision therapy may help rehabilitate the vision of stroke and trauma patients. But regarding the assertions of behavioral optometrists — that vision therapy can make a meaningful difference in the kinds of children who are commonly given diagnoses of conditions like learning disabilities, A.D.H.D., autism spectrum disorders or problems with coordination — the group issued a vote of no confidence. “The continued absence of rigorous scientific evidence to support behavioral management approaches, and the paucity of controlled trials in particular, represents a major challenge to the credibility of the theory and practice of behavioral optometry,” Brendan T. Barrett, an optometrist, concluded in the second College of Optometrists report.

The American Academy of Pediatrics also essentially declared war on behavioral optometry last summer. It reviewed 35 years of the literature in support of vision therapy and issued a statement — in conjunction with other ophthalmological associations — condemning the therapy and its contention that it could help with learning disabilities. Visual problems, it claimed, are not the basis for learning disabilities.

It issued a stern warning about the seductions of treatments that sound convincing but aren’t based on science: “Ineffective, controversial methods of treatment such as vision therapy may give parents and teachers a false sense of security that a child’s learning difficulties are being addressed, may waste family and/or school resources and may delay proper instruction or remediation.”

All this has done nothing to dampen the enthusiasm of vision therapy’s parent backers and practitioners. If anything, the constant chorus of negativity from mainstream medicine has fueled a crusade to help vision therapy spread from the rarefied realm of those who can afford it (treatment typically costs thousands of dollars out of pocket each year) to the population at large.

To that end, advocacy organizations have worked hard to publicize and gain acceptance for behavioral-optometry techniques. Some behavioral optometrists make visits to elementary schools, offering free optometric screenings. They offer continuing-education seminars for teachers and school counselors. Around the country, advocates of behavioral optometry have been pushing state legislatures to mandate that every child have a complete eye exambeyond the screening routinely performed by pediatricians before kindergarten and to require insurance companies to reimburse vision therapy. The National PTA in 1999 passed a resolution calling upon all public schools to screen for the kinds of “visual skill deficiencies” behavioral optometrists treat. (Even the N.A.A.C.P. passed a resolution, at its 100th convention last year, endorsing vision therapy as a way to help some prisoners become productive members of society.)

“It’s a big problem,” Fierson, the former chairman of ophthalmology says of the spread of vision therapy, “and it’s not going away.”

Why, given the near unanimity of the medical opinion arrayed against it, do so many parents swear by vision therapy? Why are they moved not just to pay for it but also to advocate, even evangelize for it, helping optometrists spread their influence in greater numbers of communities and schools?

The reasons have as much to do with the very appealing promises of vision therapy as with the culture of parenting today — and with the peculiar culture of parents of children with issues in particular. Vision therapy is noninvasive, nonjudgmental and logical-seeming. (If a kid has problems with reading, copying from the board, tires easily during homework and loses focus, wouldn’t it stand to reason that there’s something wrong with his eyes?) The fact that virtually no medical doctors endorse the wider claims of vision therapy means little to those who, whether because of temperament, philosophy or discouraging experience with the medical establishment, are used to going it alone when it comes to their child’s treatment.

“Vision makes sense,” says Shelly Galli, a Washington mother whose daughter, Camille, is autistic and who has spent much of Camille’s life being told by doctors that the treatments she wants to pursue won’t work.

What makes sense, too, to many parents today is that vision therapists often see children’s learning and attention problems as part of the high-pressure society that kids are forced to grow up in. While problems like A.D.H.D., dyslexia and other developmental or learning disorders are now seen by mainstream medicine as related to differences in brain structure, wiring and chemistry, the behavioral-optometry model conceives of achievement-related problems as resulting from the environment: notably, the stress of growing up in an unnatural and overly visually demanding world.

This idea — however contemporary-sounding in an era of ubiquitous computers, video games and preschool reading programs — is far from new. In the late 19th century, the ophthalmologist William Horatio Bates proposed that conditions like nearsightedness andastigmatism arose from eye and mental strain. Bates believed they could be addressed through deep relaxation of the eye induced by “palming,” or covering closed eyes with one’s palms. In the early 20th century, Arthur Marten Skeffington, an English optometrist generally considered the founding father of behavioral optometry, developed his theory of vision and described reading and other close work as “socially compulsive” and “biologically unacceptable.” A person who is “constrained” to read, he wrote, becomes “an impaired organism.”

When modern-day behavioral optometrists put this theory into practice, they talk about the demands of universal literacy. They talk about children who spend too much time indoors and not enough time outside, letting their eyes roam as their ancestors’ did, hunting and scanning the horizon for predators.

This overarching theory of eye and brain dysfunction resonates with parents, many of whom believe, as does Jeffrey Kraskin, an optometrist in Washington, that children with issues are merely canaries in the coal mine for the pathologies of our time, being labeled as “sick” when their bodies and minds can’t adapt to the accelerated demands of our era.

“A human problem becomes apparent when a demand is greater than the ability,” Kraskin says. “We’re making our demands on human beings earlier. If you push a person to do something before they’re ready, something’s got to give. And I think that when that thing gives, you see attention-deficit disorder.”

In this schema, vision therapy just undoes what culture has created. There’s nothing actually wrong with the child who’s struggling to learn or pay attention — his or her dysfunction has been caused by the outside world. This reasoning is filled with the promise that, with the right kind of care, any child can rise to any sort of opportunity. Its logic is particularly well suited to parents who believe that if they have the time and money they can — indeed, must — do all they can to give their children the best shot in life. If they have a child with issues, they must try everything, wrestle with fate and take it upon themselves to research, create and organize a treatment program for their child — no matter the personal or financial cost.

That goal, that sense of possibility, is what for the past 18 months has driven Jennifer Allred, a construction lawyer turned stay-at-home mom, to fly from her family’s home in Atlanta to Washington to take her 8-year-old son, Jack, to the Vision and Conceptual Development Center, a vision-therapy practice that operates out of a first-floor office suite downtown.

Jack was given a diagnosis at age 2 of a mixed expressive and receptive language disorder. “He was difficult but not impossible to engage,” Allred recalled one Wednesday this winter while Jack did his exercises. “He met all his developmental milestones but not as robustly as you would have expected him to. You could get him laughing and playing but only if you were, like, Bozo-the-Clown-animated. He was scared of crowds, of noise.”

Jack began occupational therapy and did a lot of floor-time therapy, a one-on-one intervention developed primarily for children with autism by Stanley Greenspan, a prominent child psychiatrist in Washington. Ultimately, Jack’s developmental psychologist judged that it was time to look at “the vision piece.” After a stint in therapy in Atlanta, mother and son began traveling to Washington.

They met with Harry Wachs, the founder of the vision center, who is considered a pioneer for having tied optometric practice to Piagetian concepts of cognitive development. Wachs met for a half-hour with Jack, who at 6½ “wasn’t reading — not close to reading,” his mother says. She recalls that Wachs told her, “There’s no reason this kid shouldn’t go to Harvard.”

Allred and Jack have flown to Washington for vision therapy every 8 to 12 weeks ever since. Jack has, at the same time, attended a mainstream private school with an adult facilitator to help him navigate the day. He recently graduated from occupational therapy and from floor-time therapy. But vision therapy remains in the mix, his mother says, even though it requires a plane ride and a hotel stay and a “ridiculous, insane cost” for the family.

Such a believer is Allred, in fact, that on the day I observed Jack’s vision therapy, she’d brought along her younger son, Wyatt, a sandy-haired 5-year-old, for a consultation.

“Wyatt’s teachers think I’m crazy,” she explained afterward. “He’s a normally developing kid. But I noticed with Wyatt, doing floor time with him, the richness of the language and the play were not there with him. I wanted to know how he was visualizing. I’m kind of probing. That’s my thing with my kids: they need to learn to be thinkers. Vision therapy is also for this.”

Some doctors suspect that what really lies behind parent and optometrists’ reports of vision therapy’s success is something called the Hawthorne effect — the fact that many problems, and mental-health problems in particular, tend to get better when they receive intensive positive attention of pretty much any kind. Working with a warm and caring specialist, getting extra parental attention, concentrating on skills that can be improved (even if it’s just a matter of performing better on repetitive tests) is self-reinforcing. Under these conditions, you can certainly see great “vision” results in kids who, physicians say, didn’t have anything wrong with their eyes in the first place. And, notes Eileen Costello, a pediatrician in Boston and co-author of the book “Quirky Kids: Understanding and Helping Your Child Who Doesn’t Fit In,” spending time and money on noble-minded alternative remedies like vision therapy may have a positive, ancillary effect on parents. “I think they’re maybe alleviating their own anxiety,” she says.

Shelly Galli, the mother of Camille, is used to dismissive attitudes from doctors. There was a time when medical specialists told her to all but give up hope that Camille would ever be able to communicate. “When my daughter was diagnosed, they told me, if she doesn’t talk by 5 or 6, she probably won’t,” she recalls. Camille didn’t. But Galli refused to give up.

Camille spent years in applied behavior analysis, the intensive one-on-one behavior training technique recommended by the National Institute of Mental Health as a therapy of proven value in helping autistic children. She did speech therapy, occupational therapy,physical therapy — plus a host of scientifically unproven, even highly controversial treatments, like chelation (intravenous infusions aimed at removing mercury and other heavy metals from her body). She now eats a special organic diet and every afternoon drinks small cups of acidophilus and vinegar to counter internal yeast. She spends 35 hours a week in a one-girl schoolroom that her parents have created for her in an unused portion of a local religious school, working with a former preschool teacher with expertise in special education. She works with an art teacher and does speech therapy twice a week, works out at a gym with trainers every day and goes to vision therapy twice a week at the Vision and Conceptual Development Center, where she does jumping jacks on a trampoline and animal walks, throws and catches a beanbag and “fixates” on pictures.

All this costs well over $100,000 a year. But now, at age 11, Camille is talking. “Talking more every day,” Galli says. And Camille is reading. “And I’m glad we didn’t listen to those people,” Galli adds. In addition to twice-weekly sessions at the vision center, Camille does follow-up exercises at home or in school. She also does additional computer exercises, which help her with “tracking” skills, according to her teacher, Colleen Bane, and also — according to the computer program’s Web site — help her develop eye-muscle strength and letter recognition and activate the visual processing center of her brain. On the day I came to see her in her classroom, she was doing a set of those exercises on her laptop computer. She kept looking away from the screen, where words flashed quickly, requiring her to track with her eyes and point with her finger. As the exercise changed to one that required her to quickly memorize a short stream of letters and type them on the keyboard, she closed her eyes entirely. She twisted around constantly, trying to get a good look at the wall clock, where the minute hand was ticking, ever so slowly, toward 3 o’clock and the release for home. This was new. In recent months, her teacher, Colleen Bane said proudly, Camille has made great progress in telling time.

Though Camille has been taking part in many types of therapy, Galli attributes much of Camille’s progress in reading, and conducting herself in the world generally, to vision therapy. The same is true for Francesca Dennis, Brian’s mother, even though during the time her son was doing vision therapy he also switched schools, a change that, Dennis told me, vastly improved his life. And Jack, the boy from Atlanta with the language disorder, began for the first time to receive speech therapy while he was doing vision therapy. When I asked Allred whether Jack’s progress might just as well have been because of his speech therapy, she said: “To be honest with you, I don’t think you can tell. From my perspective, I don’t care. Are you going to deny your kid a therapy just to see if another therapy works? I’m mostly going on my gut.”

Galli also said it was possible that Camille’s progress might be a result of her other, more proven therapies, but she added that it didn’t really matter: “We never know what it is that’s really helping. But we’re not going to take any chances. You just don’t want to lose time.”