Sudden bilateral pupil dilation in normal light, pupils responded to direct light but returned to dilated size, normalised after 10mins. Cause?

Pupil dilation. Many causes of pupil dilation, including emotions - higher levels of circulating adrenaline, which occur during times of excitement or fear. drugs - from eye drops to hallucinogenics. Especially drugs that are anticholinergic light - low light, or a problem with receiving light on the retina neurologic problem - from the optic nerve to the part of the brain that regulates the eyes.