The terms "eye pinning" and "eye flashing" both refer to a common behavioral display in pet parrot species. During this display, the bird will quickly expand and contract the pupils of its eyes.
While eye pinning is a perfectly natural response to certain types of stimulation, it can look quite bizzare to those who are new to owning birds. If you notice your feathered friend pinning his eyes, please be assured that there is no cause for alarm. In fact, your pet may just be trying to communicate with you!
It's easy to think of eye pinning as a type of body language, but it's not always easy to identify just what the parrot is trying to say when he does it. Eye pinning behavior can be a sign of happiness, contentment, excitement, curiosity, or aggression -- so it's best to analyze any observations in conjunction with other physical clues the bird may exhibit, such as lunging, hissing, head-bobbing, or feather ruffling.
In my experience, I've found that eye pinning usually means that the bird has seen or heard something that it is interested in. I often observe Oliver, my Indian Ringneck Parakeet, pinning his eyes when he is trying to learn how to say a new word.
The best way to understand what your bird means by flashing his eyes is to spend time with him and learn to read his body language. In time, you may be able to use your bird's eye pinning behavior as a tool to gauge his or her mood -- ultimately improving the quality of your interactions with your pet. Just remember that practice makes perfect! Give your pet plenty of love and attention, and he will provide you with endless opportunities to improve your understanding of avian behavior.