What can be the causes of dilated and fixed pupils?

Pressure that builds inside your brain after a head injury, stroke, or tumor can damage the muscles in your iris that normally make your pupils open and close. One or both of your pupils can become fixed in the dilated position and can't react to light. If that happens, you should see a doctor right away. read more

Well, traditionally in Medicine,"dilated and fixed pupils" are associated with severe brain damage. This is usually due to swelling of the brain, and herniation of the brain stem. It is a prelude to, or indicative of really, “brain death”. read more