[Functional vision disorder: timely examination pays off].

Patients with functional vision disorder (FVD) may present with poor visual acuity, visual field loss, or a combination of the two. This paper illustrates the utility of objective tests in diagnosing FVD. We use sweep visual evoked potentials and eye tracking as objective tests for visual acuity and visual field, respectively. These measurements should be made early in the diagnostic process because appropriate treatment becomes more difficult the longer the patient has been undergoing medical workups and referrals. Additionally, objective proof of better visual functions can be used as confirmation of the absence of a serious organic disorder. The results are used to convince patients and parents that vision is potentially much better than the patient experiences and to explain FVD. Consultation should preferably take place in a multidisciplinary setting with trained ophthalmologists and psychologists.