The Bates method is an ineffective therapy aimed at improving eyesight. Eye-care physician William Horatio Bates, M.D. (1860–1931) attributed nearly all sight problems to habitual strain of the eyes, and felt that glasses were harmful and never necessary. Bates self-published a book, Perfect Sight Without Glasses, as well as a magazine, Better Eyesight Magazine, (and earlier collaborated with Bernarr MacFadden on a correspondence course) detailing his approach to helping people relax such "strain", and thus, he claimed, improve their sight. His techniques centered on visualization and movement. He placed particular emphasis on imagining black letters and marks, and the movement of such. He also felt that exposing the eyes to sunlight would help alleviate the "strain".
Despite continued anecdotal reports of successful results, including well-publicised support by Aldous Huxley, Bates' techniques have not been objectively shown to improve eyesight. His main physiological proposition—that the eyeball changes shape to maintain focus—has consistently been contradicted by observation. In 1952, optometry professor Elwin Marg wrote of Bates, "Most of his claims and almost all of his theories have been considered false by practically all visual scientists." Marg concluded that the Bates method owed its popularity largely to "flashes of clear vision" experienced by many who followed it. Such occurrences have since been explained as a contact lens-like effect of moisture on the eye, or a flattening of the lens by the ciliary muscles.
The Bates method has been criticized not only because there is no good evidence it works, but also because it can have negative consequences for those who attempt to follow it: they might damage their eyes through overexposure of their eyes to sunlight, put themselves and others at risk by not wearing their corrective lenses while driving, or neglect conventional eye care, possibly allowing serious conditions to develop.
"Natural vision correction" or "natural vision improvement" continues to be marketed by practitioners offering individual instruction, many of whom have no medical or optometric credentials. Most base their approach in the Bates method, though some also integrate vision therapy techniques. There are also many self-help books and programs, which have not been subjected to randomized controlled trials, aimed at improving eyesight naturally. Purveyors of such approaches argue that they lack the funds to formally test them.
The heavily advertised "See Clearly Method" (of which sales were halted by a court order in November 2006, in response to what were found to be dishonest marketing practices) included "palming" and "light therapy", both adapted from Bates. The creators of the program, however, emphasized that they did not endorse Bates' approach overall.
In his 1992 book The Bates Method, A Complete Guide to Improving Eyesight—Naturally, "Bates method teacher" Peter Mansfield was very critical of eye care professionals for prescribing corrective lenses, recommending most of Bates' techniques to improve vision. The book included accounts of twelve "real cases", but did not report any information about refractive error.
Czech native John Slavicek claims to have created an "eye cure" that improves eyesight in three days, borrowing from ancient yogic eye exercises, visualizations from the Seth Material, and the Bates method. Although he has testimonials from his neighbor and others, several of his students indicate that he has greatly exaggerated their cases. Slavicek's self-published manual, Yoga for the Eyes, was rejected by an ophthalmologist who evaluated it, and evinced no interest from the World Health Organization and St. Erik's Eye Foundation in Sweden as he had not conducted double-blind tests.
The Bates Method is largely concerned with improving eyesight or acuity. As stated on the Bates Method website: The Bates Method seeks to improve, "short-sightedness (myopia), astigmatism, long-sightedness (hyperopia), and old-age blur (presbyopia)." The employ their own techniques of Palming, Sunning, Visualization, and Eye Movements. It is the Eye Movements techniques of the Bates Method that are most often confused with Vision Therapy as it is usually identified by the term "Eye Exercises". Vision Therapy is not Eye Exercises.
Unlike the Bates Method that aims to eliminate the uses of glasses altogether, prescription lenses are often a vital part of a vision therapy program. The goal of vision therapy is not to improve acuity, it is to improve binocular vision, improve visual skills, etc. Vision therapy is often prescribed for things like amblyopia (lazy eye), strabismus (crossed eye), convergence insufficiency, etc.
The techniques and technologies of Vision Therapy were reviewed and developed throughout the twentieth century by many doctors of optometry and ophthalmology and innovations in the field continue to this day.
While some people confuse Vision therapy with self-help programs of eye exercises, such as the widely advertised See Clearly Method or the long-standing Bates Method, such programs are NOT Vision Therapy. The procedures employed in Vision Therapy involve medically supervised therapeutic procedures and, in many cases, regulated medical devices are used by the optometrists.