The Eyes Have It
The term “apple of my eye” has roots back to the King James Bible, but the modern sense of a highly favored person or object goes back to the 9th century…still not too shabby in terms of long lineages. It was previously believed that the pupil of the eye was a solid object, and the term apple – another familiar sphere – came to describe it. Mind you, in these days effective eye care was in a primitive-to-nonexistent state, so eyesight was highly valued. Hence, the term lent itself to other things which were similarly precious.
Another popular eye idiom, “see eye to eye,” also has King James Bible roots, where Isaiah 52:8 reads “…for they shall see eye to eye, when the Lord shall bring again Zion.”
The term “private eye” to describe private investigators has two plausible origins. The famous Pinkerton Detective Agency, which began in Chicago in the 1850s and was the original in the business in the US, used in their logo the image of a staring eye and the words “We Never Sleep.” However, the equally likely origin is simply the letter “I” in “private investigator.”
The adult eye color of a human baby is not always knowable at birth, as there are many genes and pigments still at work. In some babies, particularly lighter-skinned ones, it may take up to 3 years for the iris color to fully establish.
The idea of an “evil eye” that brings misfortune and undoing to the victim, often after they enjoy praise or success, goes back at least 5,000 years and is still prevalent in many cultures. Many eye images worn on clothes and jewelry are mean to repel this curse.
The eye is relaxed when viewing an object about 20 feet away, and doesn’t have to bend the light rays to focus on it. This is the reason why “20/20 vision” indicates a normal ability to see at a distance, because you can see at 20 feet something you should be able to see at 20 feet away.
A “black eye” is really just a bruising of the area around the eye. The color comes from blood under the skin, like other bruises.