why are my pupils dilated?

Question

i'm in my young 20's and my pupils always been very dilated.
people mention it sometimes.
what can cause this?

Answer 1

Might be people are jelous your eyes must be looking beautiful. This artcle will help you a lot:


Mydriasis is an excessive dilation of the pupil due to disease or drugs. Although the pupil will normally dilate in the dark, it is usually quite constricted in the light. A mydriatic pupil will remain excessively large, even in a bright environment.

Constriction of the pupil is called miosis.

[edit] Mechanism

There are two types of muscle which control the size of the iris: circular and radial. The former is innervated by the parasympathetic nervous system, the latter by the sympathetic nervous system. Sympathetic stimulation of α1 adrenergic receptors causes the contraction of the radial muscle, and subsequent dilation of the iris. Conversely, parasympathetic stimulation causes contraction of the circular muscle and constriction of the iris.

The mechanism of mydriasis depends on the agent being used. It will usually involve either a disruption of the parasympathetic nerve supply to the eye (which causes contraction of the pupil), or overactivity of the sympathetic nervous system (SNS).

Atropine blocks muscarinic acetylcholine receptors. Acetylcholine (ACh) is the neurotransmitter of the parasympathetic nervous system and blocking its action means the pupil cannot constrict.

Cocaine inhibits the reuptake of noradrenaline within a nerve synapse. When a solution of cocaine is dropped into the eye, noradrenaline is no longer reabsorbed by neurons, and its levels increase. Noradrenaline, the neurotransmitter for the SNS, causes dilation of the pupil. Another drug known to cause mydriasis is MDMA (Ecstasy).

[edit] Pathological causes of mydriasis

The parasympathetic nervous supply which causes constriction of the pupil, or miosis, is supplied by cranial nerve III, the oculomotor nerve. Damage to this nerve typically manifests itself as mydriasis, because the sympathetic supply to the pupil which causes mydriasis remains unaffected, and therefore unopposed.

[edit] Mydriatics

A mydriatic is an agent which induces dilation of the pupil. Drugs such as tropicamide are used in medicine to permit examination of the retina and other deep structures of the eye, and also to reduce painful ciliary muscle spasm (see cycloplegia). The effect of administration of a mydriatic is or was sometimes called "drops in eyes".

Answer 2

See a neurologist. This could have an underlying neurological basis that should be assessed by a physician.

Answer 3

It was because of dtress for me...and a lack of self acceptance. Now that I am more content, my eyes are blue again.

Answer 4

Turn up the lights.

Answer 5

You are either:
a) drunk
b) stoned
c) all of the above

Answer 6

stop smoking that crack