To the Editor.
—The study by Drs Hammond and Schmidt1 in the January 1986 issue of the Archives on the results of vision screening of children with the Random Dot E (RDE) stereogram may give the impression that RDE testing has emerged as the ideal method to identify all vision problems that may impede normal visual development in childhood. This is certainly not so. My co-worker and I2 have previously pointed out that stereoacuity testing does not replace visual acuity testing as a screening method, since stereoacuity and visual acuity, although related, are not identical functions. For instance, patients with uncorrected anisometropia or anisometropic amblyopia may have normal stereoacuity and thus escape detection and effective treatment at an age when improvement of visual acuity is still possible. As the authors themselves point out, underreferrals not only compromise the effectiveness and credibility of the screening effort but also raise
von Noorden GK. Stereoacuity Testing Does Not Replace Visual Acuity Testing. Arch Ophthalmol. 1986;104(8):1112-1113. doi:10.1001/archopht.1986.01050200018005