Source:http://linkedlifedata.com/resource/umls/id/C0182026
UMD: Occluders designed to temporarily prevent or attenuate (i.e., occlude) the passage of light to one or both eyes. These occluders are typically a handheld plastic or metal device with one or two opaque covers for the eyes; some occluders are translucent and/or include pinholes for special tests. Ophthalmic occluders are used in tests, including for visual acuity (e.g., cover test), eye-movement monitoring, and visual field.