How to Check Pupils?

To check pupils, you need to observe their response to light, specifically looking for dilation and constriction.

Understanding Pupil Reflexes

The pupil's response to light is a critical neurological assessment. It indicates how well the brain is communicating with the eyes. Here’s a breakdown:

• Direct Response: This refers to the reaction of the pupil in the eye where the light is shone. A normal, healthy pupil should constrict (become smaller) when exposed to light.
  • As seen in the provided video, a pupil dilates nicely and briskly after the light is removed. This is the direct response.
• Consensual Response: This is the reaction of the pupil in the opposite eye when light is shone into the other. This pupil should also constrict at the same time, indicating both eyes are working together.

How to Perform the Pupillary Examination

Here's a step-by-step guide to checking pupil reflexes:

1. Prepare the Environment: Dim the lights in the room. This will allow the pupils to dilate (enlarge) naturally.
2. Gather Equipment: You’ll need a penlight (or a similar light source).
3. Patient Positioning: Ensure the patient is comfortable and can look straight ahead.
4. Observe the Pupils:
   • Note the size of each pupil before shining any light. Are they equal in size? This is called PERRLA. (Pupils Equal Round Reactive to Light and Accommodation)
5. Shine the Light: Shine the penlight into one eye at a time.
   • Observe the immediate response.
   • The pupil should constrict.
6. Observe the Consensual Response: Pay attention to the pupil in the other eye.
   • It should also constrict when the light is shined in the opposite eye.
7. Remove the Light: Quickly remove the light source from the eye.
   • Observe how quickly each pupil dilates again in the absence of the light.
8. Repeat on the Other Side: Repeat steps 5, 6, and 7 on the opposite eye.
   • This ensures you are observing the reaction in each eye separately.
9. Document Your Findings: Note your findings in the patient’s chart or as required.

Normal Findings

• Both pupils are equal in size.
• Both pupils constrict briskly when exposed to light.
• Both pupils dilate when light is removed.
• The consensual response is present.

Abnormal Findings

• Pupils are unequal in size (anisocoria).
• Pupils fail to constrict or are sluggish in their response to light.
• Pupils do not dilate.
• There is an absent or sluggish consensual response.

Why is Checking Pupils Important?

Checking pupils is an essential part of a neurological assessment because:

• Neurological Status: Pupil reflexes can indicate brain function and the potential presence of neurological issues.
• Trauma Assessment: Changes in pupil response can signify head trauma or increased intracranial pressure.
• Medication Effects: Certain medications can cause pupil dilation or constriction, and an examination can help identify these effects.
• Disease Monitoring: Specific conditions such as stroke, eye diseases, or nerve damage can affect pupil reflexes.