Vision therapy, also called orthoptics or visual training, consists of a learning process, which is intended to correct or improve certain specific visual dysfunctions identified or diagnosed by vision professionals. Vision therapy can also be used in the absence of any prior visual problem with the aim of improving the patient’s vision. This type of therapy is a complement to other interventions that different vision professionals may utilize, such as surgery, optical compensation, or medication. Therefore, it is important that the vision professionals who utilise vision therapy do so in an interdisciplinary context.
The need for vision therapy is usually determined after a complete functional vision examination in which the characteristics of the visual system are evaluated in an analytical way, i.e., every process is studied separately and, in some cases, their interactions and the values obtained are compared with the standard values expected for that particular patient. The patient’s symptoms and the visual needs are also considered.
Training programmes that are usually developed try to improve aspects of visual performance that are not performed properly. They commonly use exercises with pen and paper, computer programmes, lenses, filters, prisms, occlusion systems of one of the eyes, systems of binocular dissociation (the ability to see with both eyes, but not being able to combine each eye’s individual image into one fused image).
Visual training sessions are usually performed individually. Both the procedures used as well as the duration of the training depend on the type of visual problem, the patient’s collaboration, and the severity of the visual dysfunction that the patient presents. These trainings can be used to treat different visual dysfunctions that have previously been detected (for example, convergence failure, accommodative excess, alternating esotropia in near vision, etc.), to prevent the development of visual problems (for example, the emergence of amblyopia, or the delay in the development of stereopsis in children with maturation delays) and to improve the patient’s visual performance with specific goals (for example, in athletes, pilots, drivers, etc.).
The general areas of vision therapy intervention can include strabismic and non-strabismic binocular dysfunctions, amblyopia (commonly known as lazy eye), dysfunctions in ocular accommodation, oculomotor dysfunctions, and dysfunctions in visual cognition (perception, attention and memory problems related with vision).
Finally, the objective of any vision therapy programme aims to: reduce the patient’s symptoms, obtain the desired visual performance and normalise the patient’s visual function values.