ANATOMY

Detailed explanation-1: -Stimulation of the sympathetic pathway results in the release of norepinephrine onto -adrenergic receptors on the sphincter dilator, dilating the pupil and increasing the activation of light receptors in the retina.

Detailed explanation-2: -Stimulation of the autonomic nervous system’s sympathetic branch, known for triggering “fight or flight” responses when the body is under stress, induces pupil dilation. Whereas stimulation of the parasympathetic system, known for “rest and digest” functions, causes constriction.

Detailed explanation-3: -The pupillary dilation pathway is a sympathetically driven response beginning in the hypothalamus and ending with the contraction of the dilator pupillae muscle.

Detailed explanation-4: -The condition may be caused by dilating eye drops from an eye exam, the side effects from a drug/medication or traumatic injury. Pupils naturally dilate due to changes in light and emotional events, but unusual pupil dilation could be the result of a medical condition.

Detailed explanation-5: -Sustained sympathetic stimulation was found to cause a significant decrease in the equilibrium pressure of the eye. This stimulation was found to decrease the rate of secretion of aqueous humour but not to influence significantly the rate of drainage of aqueous humour.