Enlarged Pupils

Facts about Enlarged Pupils

            The eyes are the window to the soul; but when an unusual situation such as enlarged pupils occurs it is wise to determine the reason in order to keep those windows clear.

            The eyes are a highly complex system that allows us to continually capture images and process them into visual displays that our brain recognizes and understands.  The best way to understand the process is to consider a camera, with the exception that the eyes work together in an autonomous yet synergistic method.  The parts of the eye with which people are most familiar are the retina, lenses, iris and pupils.  Because of their important to our lives, the eyes are equipped with their own protection and defense mechanisms through tear ducts, aqueous fluids, eyelids and eyelashes.  Even with these protective measures in place, the eyes are still vulnerable to a variety of diseases, disorders and conditions that can ultimately affect vision.

            The pupil of the eye is actually just an opening to the eye that leads to the lens; no color is possessed by the pupil itself.  We see black when we look into the pupil because light that is accepted into the area is fully absorbed by the eye tissues on its way to the retina.  The purpose of this opening to the eye is to allow light to enter into the organ; controlling the amount of light that enters by dilating or constricting.  Enlarged pupils will be the result of dilation, while pinpoint pupils are the result of constriction.  The change occurs when the iris, which is commanded by two muscle groups, either lessens or increases the pupil’s size.

            While the normal process of dilation and constriction occurs numerous times daily as part of regular vision, there are also additional situations that can be the cause.  Some can be external while others are controlled by emotions.  Sometimes, the change in pupil size can occur spontaneously, such as when an individual is experiencing extreme stress or pain, or intently focusing attention on an object or person.  Emotions can dictate the size of pupils in the eye.  Fear, desire and sadness are all sentiments that invoke the enlarged size.  Certain medications and drugs also have the effect of creating enlarged pupils.  Consuming alcohol or taking opioid drugs such as morphine, codeine and methadone among many others, will actually have the reverse effect on the pupils of the eyes; constricting them to the size of pinpoints.  Others drugs, such as cocaine, amphetamines, LSD, atropine and mescaline will result in the pupils enlarging.  Even prescription medications, such as eye drops, can produce the same results.

            At times it is beneficial for the pupils to be dilated for medical reasons.  Drops are placed in the eye by a medical professional that serve to widen, or dilate the pupils.  The eye care professional is then able to see within the opening to the retina at the back of the eye and determine if any disease is present.  The enlarged pupils may remain in that condition for several hours, causing some blurred vision and difficulty seeing in bright light before returning back to its normal position.  There are also certain medical conditions that will cause the pupils to dilate.  Brain injury, stroke, tumor of the brain and rabies will all have the same effect on the pupils of the eye.

            Although the pupils of the eye increase and decrease in size as part of the normal vision process, there are instances that cause abnormal dilation or constriction of the pupil that must be investigated by a medical professional to ensure that the eyes or vision are not compromised.  Keeping the eyes as healthy as possible will provide our “windows” the best view possible.