Eyestalk

Pulmonate land snails usually have two sets of tentacles on their head: the upper pair have an eye at the end; the lower pair are for olfaction.

A stalk-eyed fly

Well-developed eye of Eustrombus gigas on eyestalk. There is a small tentacle on the eyestalk also.

In anatomy, an eyestalk (sometimes spelled as eye stalk or known as an ommatophore) is a protrusion that extends the eye away from the body, giving the eye a better field of view than if it were unextended. It is common in nature and in fiction.

In nature

In nature, eyestalks are sometimes called tentacles, and may have olfactory organs and/or eyes at the end. Examples include snails, the trilobite superfamily Asaphida, and fly family Diopsidae. The crustacean family Polychelidae have eyestalks but no eye.

In fiction

A beholder is a fictional character that sports numerous vertical eyestalks.^[1]

Many Dalek variants have a horizontal eyestalk.

Grans from Star Wars have eyestalks.

See also

Eyestalk ablation

References