Pupil dilation is also known as mydriasis. On a normal occasion, pupil dilation occurs when a person is in dark, the pupil dilates so that more light can enter the eye. However, mydriasis is a condition where there will be an unusual dilation of the pupil. Some of the causes of mydriasis are anticholinergics, injury to the eye, increased oxytocin, drug abuse such as cocaine, ecstasy, hallucinogenics, and crystal methamphetamine. Disorders such as Benign Episodic Unilateral Mydriasis, cranial nerve neuropathy and traumatic brain injury. Pupil dilation by itself is already a symptom and it can cause further complications such as photophobia, blurred vision, eye irritation, headache and dizziness. The treatment for this condition is by treating the underlying cause which causes the pupil dilation. However, the patient to be advised that they should avoid direct sunlight, do not drive especially during the day and usage of sunglass, especially in bright places.