The first step towards a correct diagnosis is to determine if the pupillary response in each eye is normal. The patient usually has no symptoms and may not be aware of the difference. Response to light and near testing is usually normal and difference in size of the two pupils is usually less than 2mm. Response to light and near testing is usually intact although anisocoria is greater in dim light.
Patients usually complain of pain, photophobia, and red eye.
It is usually bilateral and patients do not experience symptoms directly related to it. Pupils are assymetrical, irregular, and react poorly to light but constrict normally to a near stimulus. Pupil will react poorly to light and pharmacologic dilatation. Most cases are idiopathic but associations are present with viral infections, neuropathies, or trauma. Pupil is fixed and dilated with poor response to light and near.