Pupil dilation is a natural process that occurs when the muscles in the iris, the colored part of the eye, control the size of the pupil in response to changes in light. However, there are several other causes of pupil dilation, including:

• Emotional states: Pupil dilation can occur in response to emotional states such as attraction, stress, or fear. This is due to the stimulation of the autonomic nervous systems sympathetic branch, which triggers the "fight or flight" response.

• Medications: Certain medications, including dilating eye drops, anticholinergics used to treat overactive bladder, nausea, urinary incontinence, and chronic obstructive pulmonary disorder, and drugs used to treat epilepsy and other seizure disorders, can cause pupil dilation.

• Injuries and diseases: Traumatic brain injury, head injury, tumor, or stroke can cause pupil dilation.

• Recreational drugs: Stimulants and psychotropic substances, including cocaine, ecstasy, LSD, psilocybin, and amphetamines, can cause pupil dilation.

• Prescription drugs: Prescription drugs such as Botox can cause pupil dilation.

If pupils dilate suddenly, occur after a traumatic injury, or cause headaches and confusion, it is important to seek medical attention immediately. If you notice a sudden change to one or both pupils, or if you observe that your pupils frequently stay dilated, you should contact your primary care physician or ophthalmologist to make sure your eyes and vision are safe.