ophthalmoscope

n (medical 医) instrument for examining the eye closely, having a mirror with a hole in the centre 检眼镜; 眼底镜.

opera, opera-glasses, opera-house, operable, operate, operatic, operatically, operating system, operating-table, operating-theatre, operation, operational, operations room, operative, operator, operetta, ophthalmic, ophthalmic optician, ophthalmologist, ophthalmology, opiate, opine, opinion, opinion poll, opinionated, opium, opossum, opp, opponent, opportune, opportunely, opportunism, opportunist, opportunistic, opportunity, oppose, opposed, opposite, opposition, oppress,