Its Medical Name Is an Optotype
This page is the CodyCross answer for the clue below from Mesopotamia, Group 968, Puzzle 4 (Proverbs and Sayings).
Question is: Its Medical Name Is an Optotype
and the answer is: EYECHART
Word Meaning:
EYE CHART — A sign or poster showing letters or symbols in progressively smaller lines of type, used to test the acuity of distance vision.
Definitions from Wiktionary.