Retina
late Middle English: from medieval Latin, from Latin rete ‘net’.
wiktionary
From Middle English rethina, borrowing from Medieval Latin rētīna(“relating to a net”, feminine), ellipsis of tunica rētīna(“net-like tunic”), used to describe the blood vessel system at the back of the eye. The phrase is attested in the 12th century in Guillelmus the abbot and Gerard of Cremona—the latter may have created this phrase as a translation for Arabic طَبَقَة شَبَكِيَّة (ṭabaqa šabakiyya) "net-like layer", which translates Ancient Greek ἀμφιβληστροειδής χῐτών(amphiblēstroeidḗs khitṓn). [1]
etymonline
retina (n.)
late 14c., "membrane enclosing the eyeball;" c. 1400, "innermost coating of the back of the eyeball;" from Medieval Latin retina "the retina," probably from Vulgar Latin (tunica) *retina, literally "net-like tunic," on resemblance to the network of blood vessels at the back of the eye, and ultimately from Latin rete "net" (see rete).
The Vulgar Latin phrase might be Gerard of Cremona's 12c. translation of Arabic (tabaqa) shabakiyyah "netlike (layer)," itself probably a translation of Greek amphiblēstroeidēs (khiton).
