Which test is used to screen for strabismus by comparing red reflexes of the two eyes?

• A. Hirschberg
• B. Krimsky
• C. Bagolini
• D. Bruckner

Answer: (D)

The main concept is using a simple red reflex comparison to screen for eye misalignment. In the Bruckner test, you shine a light from a direct ophthalmoscope or retinoscope at about half a meter and look at the red reflections from both retinas as the patient fixes on a distant target in a dim room. When the eyes are properly aligned, the red reflexes are similar in brightness and lie roughly in the same position within each pupil. If there is strabismus, the reflexes become asymmetric—one eye’s reflex may appear brighter or darker, or the reflection may be displaced relative to the other pupil—flagging a potential misalignment. This makes it a quick, effective screening tool for strabismus and helps identify conditions like anisometropia or media differences that could affect the reflex.

For context, other tests use different cues: the Hirschberg method estimates deviation by the location of the corneal light reflex relative to the pupil center; the Krimsky test uses prisms to neutralize the reflex and quantify the deviation; Bagolini assesses binocular function with overlapping light streaks to reveal suppression or diplopia. The Bruckner test specifically centers on comparing the red reflexes, which is why it’s the best choice here.