PERRLA Eye Exam

What is a PERRLA eye exam?

PERRLA is the medical abbreviation (acronym) for the standard eye exam that helps your healthcare provider or ophthalmologist (eye specialist) determine if your pupils work as they should. It’s also called a pupillary exam.

PERRLA stands for:

• Pupils: They should be in the center of your iris.
• Equal: Healthy pupils are about the same size.
• Round: Your pupils should look like circles with even borders.
• Reactive: This refers to how pupils react. Healthy pupils open or close in response to light.
• Light: Your provider shines a light in your eyes to see if your pupils close to protect your vision.
• Accommodation: Healthy eyes respond in the same way. They should quickly shift focus between objects, places, animals and people that are close (pupils grow smaller) and far away (pupils get wider).

Providers use PERRLA during routine eye exams, neurological checkups and medical emergencies. Most people receive normal test results. Unusual results typically require additional testing to confirm a diagnosis and guide treatment.

When is a PERRLA test performed?

A provider may do a PERRLA assessment during a routine eye exam or physical exam to check your vision and health. You may also receive a PERRLA test if your eye is injured or damaged or you experience vision or neurological issues.

How does the PERRLA test work?

Your provider or eye care specialist (ophthalmologist) uses a small handheld light and object, like an index finger or pen, to check the health of your pupils. You sit still in a dim room and follow your provider’s instructions on where to look.

What should I expect during the PERRLA test?

During a PERRLA exam, your provider:

• Looks into your eyes and measures pupil shape and size.
• Moves a flashlight back and forth in front of your eyes every two seconds while you look straight ahead, called the swinging light test or Marcus Gunn test.
• Shines a light in one eye, then the other and then repeats, called the light reflex test.
• Asks you to focus on a small object (finger or pen) and moves it far away from your face, then close to your face and then from side to side.
• Checks pupil reactions when focusing on a distant object, called the near reflex test.

When should I know the results of the PERRLA test?

You typically receive the results of your PERRLA exam right away. Talk to your provider if you have questions about your vision and eye health.

What do unusual or abnormal PERRLA test results mean?

PERRLA test results may signal a problem with your eye health or vision. In some cases, you may need contact lenses or eyeglasses to correct vision issues. Results can also suggest an underlying medical condition. In this case, your provider typically recommends more tests.

What conditions can PERRLA help detect?

Abnormal PERRLA results may serve as a warning sign for conditions like:

• Anisocoria.
• Adie’s pupil, where one larger-than-normal pupil doesn’t constrict in bright light.
• Argyll Robertson pupils, a sign of late-stage syphilis, where small pupils get smaller when looking at nearby objects but don’t respond to bright light.
• Eye trauma, like a scratched eye (corneal abrasion) or muscle damage.
• Glaucoma.
• Horner syndrome, a disorder of the nerves that connect your brain to your eye.
• Optic nerve problems, like optic neuritis.

Unusual results on a PERRLA test may be a sign of brain conditions, including:

• Aneurysm.
• Brain lesion.
• Brain tumor.
• Concussion.
• Seizure.
• Stroke.