Frenzel's ophthalmoscopy

Frenzel's glasses examination method is one of the nystagometry methods, because the subject's pupil has been illuminated and enlarged by a convex lens, and the nystagmus can be seen more clearly. The subject wears this glasses to check in the dark room. This mirror is a convex lens with a diopter of 15D ~ 20D, and there is a small light bulb next to the mirror. Since the pupil of the subject has been illuminated and enlarged by the convex lens, it is more clear to observe the nystagmus. Basic Information Specialist Category: Ophthalmic Examination Category: Other Inspections Applicable gender: whether men and women apply fasting: not fasting Tips: Inappropriate crowd: vestibular function is intact. Normal value I° nystagmus only appears when gazing toward the fast phase side; II° has nystagmus toward the fast phase side and forward anterior gaze; and nystagmus occurs when III° is gazing forward and in the direction of fast and slow phase. Clinical significance Abnormal results often have autonomic symptoms such as dizziness, nausea and vomiting, and the severity is consistent with the intensity of nystagmus. For central spontaneous nystagmus, the nystagmus can be vertical and rotational; the direction can be changed; the intensity is unchanged; there can be no autonomic symptoms, and the severity is inconsistent with the nystagmus intensity. Need to check the crowd of people with nystagmus, vertigo. Precautions Taboo before inspection: Do not allow too much light. Requirements for inspection: The subject wears this glasses. Inspection process The subject wears this glasses to check in the dark room. This mirror is a convex lens with a diopter of 15D ~ 20D, and there is a small light bulb next to the mirror. Since the pupil of the subject has been illuminated and enlarged by the convex lens, it is more clear to observe the nystagmus. Not suitable for the crowd Inappropriate crowd: the vestibular function is intact.