It's caused by inflammation in the uvea, a layer of tissue just inside the outer white part of your eye. The uvea is made up of a layer of blood vessels, a muscular ring that surrounds your pupil ...
The middle layer of the eye, known as the uvea, becomes inflamed when someone has eye inflammation or uveitis.
Uveitis: Inflammation of the uvea, the middle layer of the eye. Squinting or Blinking: Indicative of eye discomfort or pain.