Illuminated frenzel glasses are used in detecting-: (A) Nystagmus, (B) Heterophoria, (C) Esotropia, (D) Astigmatism
Answer is A. Frenzel goggles are a diagnostic tool used in ophthalmology, otolaryngology and audiovestibular medicine for the medical evaluation of involuntary eye movement (nystagmus). They are named after Frenzel, a German physician Ref AK khurana 6/e p515