"The markings on the sides of the stone indicate that it was once set in something."
— Item examination
Green Eyes are treasure items found in Resident Evil 4. They are small jewels that can be fitted into the Butterfly Lamp, along with the Red Eye and Blue Eye. It is worth 1,000₧ if sold by itself.
They are dropped by the Novistadores and is the most common eye to find. To acquire this, kill a Novistador when it has spotted you. Two drop from shooting down the nest in Chapter 4-2. In Separate Ways, one is found in the Prison area in the back right cell.