眼科
がんか · ganka · JLPT N1 · noun
ophthalmology
眼 — eye radical 目 + 艮 (phonetic)
眼 is a semantic-phonetic compound. The left side 目 means 'eye' and gives the meaning, while 艮 on the right supplies the sound. Originally referring to the eyeball, it broadened over time to mean 'eye' generally and, by extension, 'a hole' or 'key point'.
科 — grain 禾 + measure 斗
科 combines 禾 (grain) and 斗 (a dipper/measure), originally depicting the act of measuring or grading grain. From this, it extended to mean classification, category, and branch of study. Today it commonly appears in words for science (科学) and academic disciplines.