The corneal light reflex test is used to detect heterophoria and help differentiate true strabismus from peudostrabismus.
Performing the Test
Hold a penlight or ophthalmoscope 30-50 cm in front of the patient
Have the patient fixate on the light
Note the position of the point of light, the reflection on the cornea, in each eye
The test is normal if the reflex falls symmetrically on each cornea.
If the reflection on the deviated eye is displaced laterally, the eye is said to be esotropic
If the reflection on the deviated eye is displaced medially, the eye is said to be exotropic
References
Swartz MH. Textbook of Physical Diagnosis: History and Examination. Philadelphia: W.B. Saunders Company; 2002.
Bickley LS, Szilagyi PG. Bates' guide to physical examination and history taking. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2009.
Behrman RE, Kliegman, RM, Jenson HB. Textbook of Pediatrics. 17th edition. Saunders; 2003.
Kleigman, R., Stanton, B., Schor, N., Behrman, R. Nelson Textbook of Pediatrics, Saunders, 2011