Hirschberg Test (Corneal Light Reflex): How Eye Alignment Is Checked
Updated: 2 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: November 2026 · How we review
Quick Answer
The corneal light reflex test, also called the Hirschberg test, is a painless way to check whether the eyes are aligned. A provider shines a light at the eyes and looks at where the reflection lands on each cornea. Reflections in different spots may point to strabismus. It's a screening test, so suspected misalignment is confirmed with other tests.
What the research says
The Hirschberg test estimates, but doesn't precisely measure: when 16 experienced strabismus specialists judged eye misalignment from photos, the Hirschberg and Krimsky methods were substantially less accurate than the alternate prism and cover test, and larger angles were often underestimated (Choi RY et al., Ophthalmology, 1998) [2]
Light reflex photos can miss strabismus: in 100 children screened with a photoscreener whose photos were graded by the position of corneal light reflexes, sensitivity for strabismus was only 23% to 50%, with specificity of 76% to 96%, so the authors urged caution in relying on photos alone (Simons BD et al., Ophthalmology, 1999) [3]
Key takeaways
The Hirschberg test checks eye alignment using a light reflection.
It's quick, painless and suitable for infants.
Matching reflections in both eyes mean the eyes are aligned.
Facial features can cause "false" misalignment (pseudostrabismus).
Abnormal results are confirmed with more precise tests, such as the cover test.
What is the Hirschberg test?
The test is named after Julius Hirschberg, who created it. The cornea, the clear front surface of the eye, reflects light like a mirror. When both eyes look at the same light, the reflections should be centered in the same spot. A shift in one eye suggests that eye is turned. Eye specialists, pediatricians and other providers use it, including during physical and neurological exams, since sudden misalignment can signal a brain problem such as a stroke or concussion. Sources: [1]
How it's done
The test takes a minute or two.
The room lights are dimmed.
Your provider faces you and holds a small light, such as a penlight, in front of your eyes.
You look at the light.
Your provider compares where the reflection falls on each cornea. Sources: [1]
What the results mean
The direction of the shift shows which way the eye turns.
Finding | What it means |
Reflections match in both eyes | Normal alignment ("ortho") |
Reflection shifted toward the outer edge | The eye turns inward (esotropia) |
Reflection shifted toward the nose | The eye turns outward (exotropia) |
Reflection shifted down or up | The eye turns up (hypertropia) or down (hypotropia) |
Sources: [1]
Pseudostrabismus and limitations
A screening result needs confirmation.
Some babies look cross-eyed because of a wide, flat nasal bridge or skin folds at the inner corners of the eyes. This pseudostrabismus looks like misalignment, but the light reflexes are symmetric. The Hirschberg test also only estimates the size of a turn and can miss small or intermittent misalignment, so providers confirm findings with tests such as the cover test and prism measurements. Sources: [1, 2, 3]
Next steps after an abnormal result
Children with suspected misalignment should see a provider promptly, because amblyopia (lazy eye) is most treatable when caught early.
Pediatricians and primary care providers refer to an ophthalmologist for a full exam.
Treatment may include glasses, patching or strabismus surgery.
Sudden misalignment, especially after a head injury or with stroke warning signs, needs emergency care; call 911. Sources: [1]
Conclusion
The Hirschberg test is a simple light check that helps spot eye misalignment, even in babies. It's a fast first step; if the reflections don't match, more precise tests confirm the problem so treatment can start early.
Keep learning: read about lazy eye (amblyopia) and the eye exam.
Frequently asked questions
What is the Hirschberg test?
A test that checks eye alignment by looking at light reflected from the corneas.
What is the corneal light reflex?
The reflection of a light on the clear front surface of the eye.
Does the Hirschberg test hurt?
No. It's quick and painless.
How long does it take?
About a minute or two.
Can babies have this test?
Yes. It's commonly used for infants and children.
What does a normal result look like?
The reflection sits in the same spot in both eyes.
What is pseudostrabismus?
Eyes that look misaligned because of facial features but are actually aligned.
Is the Hirschberg test accurate?
It's a good screening test but only estimates misalignment.
What happens if the test is abnormal?
You'll be referred for more precise eye tests.
When is misalignment an emergency?
When it starts suddenly, especially after a head injury or with stroke signs.
Related Reading
Eye Exam: What Happens, Tests Included and How Often to Go the full exam where this test is often done.
Esotropia (Crossed Eyes): Causes, Types, Symptoms, and Treatment a common type of eye misalignment.
Lazy Eye (Amblyopia): Symptoms, Causes, Treatment & Complete Guide a vision problem misalignment can cause.
Strabismus Surgery: How Eye Muscle Surgery Realigns the Eyes, Recovery and Risks surgery to realign the eyes.
Retinoscopy: How Eye Doctors Measure Your Prescription another eye test used for young children.
References
Cleveland Clinic. Corneal Light Reflex (Hirschberg) Test: What It Is. Cleveland Clinic. Last updated April 17, 2025. https://my.clevelandclinic.org/health/diagnostics/corneal-light-reflex-hirschberg-test
Choi RY, Kushner BJ. The accuracy of experienced strabismologists using the Hirschberg and Krimsky tests. Ophthalmology. 1998;105(7):1301-1306. PMID 9663237. https://doi.org/10.1016/S0161-6420(98)97037-3
Simons BD, Siatkowski RM, Schiffman JC, et al. Pediatric photoscreening for strabismus and refractive errors in a high-risk population. Ophthalmology. 1999;106(6):1073-1080. PMID 10366073. https://doi.org/10.1016/S0161-6420(99)90243-9
Medical disclaimer
This article is for general education only and does not replace advice from a qualified healthcare professional. Talk to your doctor about your own diagnosis and treatment, and seek emergency care right away for severe or sudden symptoms.
Comments