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What is the Pupil of the Eye?

The pupil of the eye is the black circle in the center of the iris. The iris is the colored portion of the eye with a structure and color unique to each person. 

The pupil of the eye is a portal which admits and regulates the flow of light to the retina. This is part of the process which allows us to perceive images. The pupil opens and closes to control the amount of light that is allowed to enter the eye. From the outside of the eye, light passes through the clear lens, then through the pupil. This light is then focused on the retina, which is the layer of light sensitive cells at the back of the eye.

When it is dark, our pupils dilate or open wider to allow more light in. Doing this maximizes our vision. In  bright light, our pupil shrinks to a very small diameter to protect the sensitive photoreceptors in our retina.

This is exactly the role that the pupil plays in the eye. The pupil reacts to external light and changes its size accordingly. That is why when we go into bright sunlight, we involuntarily squint – we almost close our eyes to limit the sudden excess of light entering. Once the pupils have adjusted to the light by becoming smaller, we no longer need to squint. Similarly when we go into a dark room it takes a few moments for our pupils to open wide so that the eyes can receive the maximum possible light to be able to see as much as possible.

There are times when the external light is so bright that even when the pupils are at their smallest, the amount of light entering the eye is still too much for the retina to accept comfortably. That’s why wearing dark glasses, which reduce the amount of light, brings such relief.

The pupils also react to certain emotions and this can make them change their size. They tend to become small when a person is angry or doubtful, and open wider when a person is pleased or surprised. To lean more about the pupil or other parts of the eye, contact Skyline Vision Clinic at 719-630-3937 or website to schedule an appointment with Dr. Buckley.