afterimage test
The afterimage test, or Hering-Bielschowsky afterimage test, assesses retinal correspondence from the positions of two afterimages, a horizontal one in one eye and a vertical one in the other.1,2 A camera flash masked to a narrow slit imprints each afterimage while the patient fixates a mark at the center of the slit. The mark shields the fovea, so each afterimage appears as a line with a gap at the fovea.1
Afterimages imprinted on the two foveae appear in their common visual direction, whatever the positions of the eyes.1 If the two gaps superimpose and the lines form a cross, retinal correspondence is normal (NRC). If the gap in the vertical afterimage appears to the left or right of the gap in the horizontal one, the two foveae have different visual directions, and correspondence is anomalous (ARC).1,2 Once imprinted, the afterimages keep their relative position through any later eye movement, which gives the test an advantage over every other test for retinal correspondence.1
More detail
The fixating eye receives the horizontal flash first, and the habitually deviated eye then receives the vertical flash, so results read the same way in every patient.1 Children as young as 4 years can perform the test. Patients with wandering or eccentric fixation are excluded, because an afterimage made in an eccentrically fixating eye takes a secondary visual direction.1 Suppression of the poorer eye or alternating fixation can keep the patient from seeing both afterimages.1
A patient with intermittent exotropia may see a cross with the eyes aligned and separated afterimages with one eye deviating. The afterimages cannot move on the retina, so the change reflects a shift from normal to anomalous correspondence.1 The test is recommended for assessing correspondence in divergence excess, and the patient must be dissociated while reporting where the afterimages lie.2
Sources (8)
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 13
- Scheiman and Wick, Clinical Management of Binocular Vision, ch. 10
- Brock, F.W. and Givner, I. (1952) 'Fixation anomalies in amblyopia', Archives of Ophthalmology, 47(6), pp. 775–786.
- Burian, H.M. (1951) 'Sensorial retinal relationship in concomitant strabismus', Archives of Ophthalmology, 45(4), pp. 373–394.
- Hansen, A.K. (1954) '"After-image transfer test" in anomalous retinal correspondence', A.M.A. Archives of Ophthalmology, 52(3), pp. 369–374.
- Jaffe, N.S. (1954) 'A simple test for anomalous retinal correspondence', American Journal of Ophthalmology, 38(1), pp. 27–32.
- Nayak, B.K. and Ghose, S. (1987) 'A simple method of detecting abnormal retinal correspondence', British Journal of Ophthalmology, 71(2), pp. 126–128.
- Rutstein, R., Daum, K. (1997) Anomalies of Binocular Vision: Diagnosis & Management, Mosby.
Reviewed October 2026