Meaning
A single human eye, wide open and looking straight ahead. Literally it represents sight.
It suits watching, noticing and the slightly eerie feeling of being observed. It is famous in the 👁️👄👁️ combo, a stunned blank stare at something absurd. Compared with 👀, a single eye feels more intense. Example: “Just saw the price of concert tickets 👁️👄👁️”.