n. goddess of rainbow; rainbow; prismatic play of colors; something that forming the colored portion of eye
If there is no iris in the eye it is impossible to control the inlet of light.
Sentence in Classic:
Their gaze began with a defiant note but was confused by what seemed a deliberate swoon of the pupil into the iris, revealing for an instant a temperament of great sensibility.
I think the ground is full of daffodils and snowdrops and lilies and iris working their way out of the dark.
The Secret Garden By Frances Hodgson Burnett Context
Then Juno omnipotent, pitying her long pain and difficult decease, sent Iris down from heaven to unloose the struggling life from the body where it clung.