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What is a Pupillometer?

Tricia Christensen
Tricia Christensen
Tricia Christensen
Tricia Christensen

A pupillometer is a device that measures the reactivity of the eyes' pupils. The pupillometer can be a large machine, connected to a wall, with a chair that allows one to sit and go through about 10 minutes of testing to evaluate the pupil’s reactivity to light. Handheld pupillometers are often used in preliminary examinations of patients who are suspected of being under narcotic influence, or for those who have sustained a significant head injury.

The pupillometer is used in many different applications. Those who are being examined for Parkinson’s disease, rheumatoid arthritis or lupus, may all show significant difference in pupil size or reactivity. In these cases the pupillometer can be an important diagnostic device that can show signs of such illnesses. In other cases, the pupillometer might be used to assess degeneration of eye tissue in people with severe diabetes.

A person with dilated pupils.
A person with dilated pupils.

Pupillometer examinations are frequently conducted on those undergoing physical exams to become firemen, emergency workers, or policemen. The reactions of the pupil can, of course, suggest the use of narcotics, especially when the pupil remains less reactive and small. The pupillometer may also suggest early symptoms of progressive joint or tissue disorders, which would disqualify one to serve as an emergency or law enforcement worker.

A pupillometer is sometimes used to study people with sleep difficulties.
A pupillometer is sometimes used to study people with sleep difficulties.

Law enforcement officials and doctors often use hand pupillometers to assess those behaving as if they are under the influence. Since viewing the eye is non-invasive, it can be a helpful and safe tool for assessing someone who may have taken narcotics. When an overdose of narcotics is suspected, doctors can then evaluate the pupils for signs of constriction, and treat patients according. This use of the pupillometer is safer than methods that involve potential contact with bodily fluids, such as in urine and blood tests.

Handheld pupillometers are often used to examine patients following head trauma.
Handheld pupillometers are often used to examine patients following head trauma.

Perhaps one of the most interesting applications of the pupillometer is its use in the study of people with sleep difficulties. Those who are exhausted, or who suffer from narcolepsy frequently have either small, nonreactive pupils in the dark, or overly reactive pupils. These studies are still in preliminary stages but may prove helpful in determining whether treatments for sleep disorders are effective. Theoretically, those who are being treated for sleep disorders would gradually show more normal pupil reactions during pupillometer examinations. Failure to improve would be a sign that treatments were not effective.

An ophthalmologist may use a pupillometer to assess diabetes-related degeneration of eye tissue.
An ophthalmologist may use a pupillometer to assess diabetes-related degeneration of eye tissue.

One criticism of this current application is that pupil fluctuations are graphed and interpreted, and a graph may be subject to several interpretations. That makes this new study somewhat less scientifically correct, though the experiment may still be helpful in addressing sleep disorders at a future date.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent TheHealthBoard contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...
Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent TheHealthBoard contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...

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    • A person with dilated pupils.
      By: Johanna Goodyear
      A person with dilated pupils.
    • A pupillometer is sometimes used to study people with sleep difficulties.
      By: bramgino
      A pupillometer is sometimes used to study people with sleep difficulties.
    • Handheld pupillometers are often used to examine patients following head trauma.
      By: corepics
      Handheld pupillometers are often used to examine patients following head trauma.
    • An ophthalmologist may use a pupillometer to assess diabetes-related degeneration of eye tissue.
      By: Monkey Business
      An ophthalmologist may use a pupillometer to assess diabetes-related degeneration of eye tissue.