The iris contracts (gets smaller). If this doesnt happen, its a good indication of head trauma/concussion, etc.
the pupil will get smaller when exposed to light, bigger when there is less light
It constricts (gets smaller).
The pupil is the part of the eye through which light passes.
The pupil allows light to enter the eye.
The iris is the coloured membrane in the eye that controls the amount of light entering the eye by expanding and contracting. The pupil is a hole in the centre of the iris. By expanding, more light will enter the pupil and by contracting less light will enter the pupil.http://en.wikipedia.org/wiki/Iris_(anatomy)
Pupil Dilates
The iris has an opening, called the pupil, through which light enters the eye.
When exposed to a bright light, the pupil of the human eye will contract. This action allows less light to come in contact with the lens.
When a light is not shined into an eye the pupil contracts gets bigger because the eye needs all the light being presented to it. If the light is not taken away the pupil does not dilate. PS like the eye gets smaller in the light.
An Argyll Robertson pupil is a bilateral small pupil of the eye which reduces in size when the patient focuses on a near object but does not constrict when exposed to bright light - a sign of neurosyphilis.
The pupil is the part of the eye through which light passes.
The pupil allows light to enter the eye.
When the eye detects bright light, the iris expands causing the hole at its centre (the pupil) to shrink in size. The brighter the light the smaller the pupil becomes. This happens because, in a dark place, the eye needs to take in as much light as possible to see better so the pupil expands; in a light place, the eye could be damaged due to over exposure to light so the pupil shrinks. The scientific word for "shrinks" is "contracts"
The iris is the coloured membrane in the eye that controls the amount of light entering the eye by expanding and contracting. The pupil is a hole in the centre of the iris. By expanding, more light will enter the pupil and by contracting less light will enter the pupil.http://en.wikipedia.org/wiki/Iris_(anatomy)
The pupil lets light into the eye.
Pupil Dilates
The iris has an opening, called the pupil, through which light enters the eye.
Smaller because the eye is protecting it's self from the light
The Lens. The Iris controls the amount of Light reaching the Retina.