Optotypes

Part of speech: noun

Definitions

1. Visual symbols or characters used in vision tests to assess visual acuity
2. Typically comprising letters, numbers, or shapes used to determine eyesight quality
3. Instruments used by eye care professionals to evaluate the clarity of vision using standardized figures

Etymology: "Optotypes" is the plural of "optotype," a compound built from the combining form "opto-," from Greek "optos" meaning "seen" or "visible" (related to the Greek verb "optesthai," "to see"), and "-type," from Greek "tupos," meaning "impression" or "figure." The result is a term for a standardized visual target: the letters, numbers, shapes or symbols on an eye chart that a patient reads to measure how sharply they can see. The pieces make the sense plain. The "type" element is the same one found in words such as "stereotype" and "prototype," where it denotes a mark, model or pattern pressed into shape, so an optotype is a deliberately designed figure whose form is fixed so that results can be compared from one test to the next. The word is a modern technical coinage built from classical elements, so it does not descend from any ancient term for eye tests.