The eye and the ear each supply a dense family of combining forms, and both families are ordered by anatomy — front to back through the eye, outer to inner through the ear. Walk them in order and the vocabulary arrives in order. Then transform the Greek and Latin plurals, and finish by flagging the eye and ear abbreviations that are no longer safe to write on a chart.
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Start on the left. Every answer here comes with the reason it is right and the look-alike it is most often confused with.