Medical conditions that cause eye dilation include brain tumors, cerebral edema, trauma, intracranial hemorrhage and elevated intracranial pressure. Other causes of eye dilation are drug overdose, low ambient light, sexual arousal, skull fracture and poisons, according to MedicineNet.
Widening of pupils causes eye dilation. Pupils dilate to allow light enter the retina. Mydiatrics help in eye dilation during ophthalmologic examinations. Eye dilation remains unchanged in the presence of strong light if caused by an abnormal response. Dilation of one eye indicates brain injury and increased intracranial pressure, says MedicineNet.
Meningitis, migraines, seizures, aneurysm and bleeding into the skull also cause abnormal eye dilation. Consult a doctor if pupil size changes after a head injury or a severe headache. Also, seek immediate medical attention if symptoms such as vision loss, eye pain and light sensitivity occur. Diagnostic tests to determine the cause of abnormal eye dilation include a blood differential, lumbar puncture and complete blood count, states Healthline.
Eye dilation helps doctors diagnose conditions such as diabetes, hypertension, retinal detachment and glaucoma. Abnormal eye dilation causes blurred vision, according to Mayo Clinic.
Insufficient oxygen supply to the brain, Adie’s pupil, cocaine use, methamphetamine use, and certain medications also cause abnormal eye dilation, says WebMD.