Management of functional vision loss

Background: Functional vision loss is a general term used to describe vision loss not associated with organic disease. Such cases are major challenges to the practitioner and demand a special workup. Methods: Patients may manifest symptoms in typical ways that should alert the examiner to the possibility of functional vision loss. In addition, a variety of techniques help distinguish functional from organic causes of vision loss. These techniques include standard tests that yield characteristic findings in functional vision loss, as well as problem-specific procedures that have the specific aim of detecting functional vision loss. Techniques are described according to whether they are useful in monocular or binocular vision loss and in cases of moderate or severe vision loss. Results: Three cases that illustrate the use of standard and select techniques to detect functional vision loss are presented. Differential diagnosis of functional from organic vision loss and special considerations in the management of patients with functional vision loss are also discussed. Conclusions: Although it is necessary to rule out underlying pathology in all cases of vision loss, a variety of techniques can provide positive evidence of functional vision loss.