Inoculate, its Past and Present
(Latin: oculus used as a reference to "eye" to designate something that looks like or is suggestive of a person's organ of sight including potato "eyes")
The verb inoculate and the noun inoculation both refer to the "eye"
These terms are used as references to something that looks like or is suggestive of a person's organ of sight. Undeveloped buds on a potato are common examples of the use of eye.
In the eighteenth century, medical researchers discovered that introducing a small amount of an infective agent into someone made that person immune to a normal attack of the same disease.
The idea of implanting, or grafting, a bud into another plant carried over into the process of inserting an infective agent into the body; and so, inoculate and inoculation have become more common for their medical applications than for their botanic procedures.
The words inoculate and inoculation were originally gardening terms; however, when a doctor inoculates anyone, the person is being "planted" in the body with a small seedling of a germ that causes the disease in order to make the person immune to a more serious attack.
As stated earlier, the word inoculate at first was a purely horticultural term and meant to insert an eye, or bud, into a plant for propagation.
Other "eye" words from ocul- are available.