Eyeglasses, Nystagmus Test
Definition : Eyeglasses designed to facilitate tests for evaluation of nystagmus based in the assessment of involuntary movement of the eyes due to external stimuli, such as rotation and/or shaking of the head or by warming and/or cooling the middle ear using liquids or air. These devices are typically eyeglasses with lenses that are capable of magnifying and illuminate the eyes while minimizing fixation during the examination (known as Frenzel lenses); the lenses may be hinged to so they can be folded out of the line of vision. The eyeglasses also include a head strap for secure fixation, batteries, and a lamp to provide internal spectacle illumination, isolating the patient from the environment in a dark room to facilitate observation of his/her eyes. Nystagmus test eyeglasses are typically used to evaluate pathological nystagmus, usually as a result of damage to the vestibulocochlear nerve (which provides hearing and helps with balance), permitting the determination of whether ear nerve damage is the cause of dizziness or vertigo. Nystagmus test eyeglasses that incorporates infrared video cameras to perform videonystagmography tests are also available.
Entry Terms : "Frenzel Lenses Eyeglasses" , "Nystagmus Test Eyeglasses" , "Nystagmus Test Goggles" , "Goggles, Nystagmus Test" , "Frenzel Lens Eyeglasses"
UMDC code : 23514