耳聪目明

ěr cōng mù míng

sharp of hearing and sight; still with all one’s faculties

Character by character

耳ěr
ears

聪cōng
keen

目mù
eyes

明míng
bright

爷爷八十多岁了，依然耳聪目明，每天还看报纸。

Grandpa is over eighty and still sharp of eye and ear; he reads the paper every day.

Tone: positive (praise).

聪 first meant keen hearing (hence the ear radical in 聪明). Said above all of old people in good health; figuratively, of someone well informed.

Learn this in Lesson 164 · HSK 7–9: 看不见的世界 (A world without sight)

A dialogue, a reading, word cards with audio and a drill that uses it, in Learn Chinese with Bao. The first lessons of every level are free.