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.^[1]

In anatomy, an eyestalk (sometimes spelled eye stalk and also known as an ommatophore) is a protrusion that extends an eye away from the body, giving the eye a better field of view.^[1] It is a common feature in nature and frequently appears in fiction.^[2]

^ ^a ^b "Slug and Snail Anatomy". All About Slugs. Retrieved 7 December 2015.
^ Allayie SA, Ravichandran S, Bhat BA. Hormonal regulatory role of eyestalk factors on growth of heart in mud crab, Scylla serrata. Saudi J Biol Sci. 2011;18(3):283-286. doi:10.1016/j.sjbs.2011.02.003

[sluganatomy-1] "Slug and Snail Anatomy". All About Slugs. Retrieved 7 December 2015.

[2] Allayie SA, Ravichandran S, Bhat BA. Hormonal regulatory role of eyestalk factors on growth of heart in mud crab, Scylla serrata. Saudi J Biol Sci. 2011;18(3):283-286. doi:10.1016/j.sjbs.2011.02.003

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