Hirschberg Test (Corneal Reflex Test)- Everything You need to Know.

What is Hirschberg Test?

• The Hirschberg test is an objective test performed with a simple pen torch and gives rough objective estimation of the angle of a manifest squint.
• It uses the 1st purkinje image to assess alignment of the eyes or potential strabismus. Being an objective test, it can be used in young or uncooperative patients or when fixation in deviating eye is poor.
• The Hirschberg test is also known as the corneal light reflex test because in this test we assess the reflex of point light source in patient’s eye.

Horizontal ad inbetween blog:

Procedure of Hirschberg Test:

• The patient sits at a distance of 50 cm from the examiner.
• The examiner turns on the penlight and directs it toward the midline of the nose (middle of eyes).
• Instruct the patient to look at the light.
• Now, Examiner placing his eyes directly behind the penlight.
• Observe the corneal light reflex from both eyes.
• The degree of strabismus can be roughly estimated by measuring the decentration of the reflex from the center of the pupil in millimeters.
• One millimeter of the deviation of the reflex is equal to 15 prisms.

Interpretation of Hirschberg Test:

Observation:

• Reflection is centred in each pupil.

Interpretation:

• Orthoposition or Normal alignment.

Horizontal ad inbetween blog:

---

Observation:

• Reflection is decentered Temporally from center of Pupil.

Interpretation:

• Esotropia.

---

Observation:

• Reflection is decentered Nasally from center of Pupil.

Interpretation:

• Exotropia.

Horizontal ad inbetween blog:

---

Observation:

• Reflection is decentered Downward from center of Pupil.

Interpretation:

• Hypertropia.

---

Observation:

• Reflection is decentered Upward from center of Pupil.

Interpretation:

• Hypotropia.

Horizontal ad inbetween blog:

---

Observation:

• Corneal Reflex is in between center of pupil & pupillary Margin.

Deviation:

• 7 degree or 15 PD

---

Observation:

• Corneal Reflex is at pupillary Margin

Deviation:

• 15 degree or 30 PD

---

Observation:

• Corneal Reflex is in between pupillary Margin & Limbus.

Deviation:

• 30 degree or 60 PD

Horizontal ad inbetween blog:

---

Observation:

• Corneal Reflex is at Limbus.

Deviation:

• 45 degree or 90 PD

---

Observation:

• Corneal Reflex is at Sclera.

Deviation:

• More than 45 degree or more than 90 PD

---

Horizontal ad inbetween blog:

Interpretation Summary:

Corneal Reflex	Interpretation
At Center	Orthophoria
Decentered Nasally	Exotropia
Decentered Temporally	Esotropia
Decentered Upward	Hypotropia
Decentered Downward	Hypertropia
Reflex is in between center of pupil and margin of pupil	7 Prism diopters
Reflex is at Margin of pupil	15 prism diopters
Reflex is in between pupil margin and limbus	30 Prism Diopters
Reflex is on Limbus	45 Prism Diopters
Reflex is on Sclera	More than 45 Prism Diopters

---

Tips in Hirschberg Test:

• Corneal reflex shift opposite to the deviation of eye.
• The higher the deviation, the more the corneal reflex decentration.

---

Question for You:

Question-1: 1 mm of the deviation of the corneal reflex is equal to ……. Prisms.

• A. 10 Prim Dioptres.
• B. 15 Prim Dioptres.
• C. 20 Prim Dioptres.
• D. 25 Prim Dioptres.

Type your Answer in Comment Box

Horizontal ad inbetween blog:

Q-2: If the Corneal Reflex is at Limbus, the amount of deviation is …………… .

• A. 15 Degrees.
• B. 30 Degrees.
• C. 45 Degrees.
• D. >45 Degrees.

Type your Answer in Comment Box

---

• Check Our Courses: Ophthalmic Instrumentation, Clinical Refraction, Contact Lens, Binocular Vision, Dispensing Optics, MCQs in Optometry
• Download our App “Optometry Notes & MCQs” from Google Play Store.