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March 1981

A Comparison of the Frisby, Random-Dot E, TNO, and Randot Circles Stereotests in Screening and Office Use

Author Affiliations

From the Department of Ophthalmology, Albany (NY) Medical College of Union University. Dr Simons is now at Wills Eye Hospital, Philadelphia.

Arch Ophthalmol. 1981;99(3):446-452. doi:10.1001/archopht.1981.03930010448011

• Three random-dot stereogram (RDS) tests, the Frisby, Random-Dot E (RDE), and TNO tests, and a stereotest with monocularly visible contours, the Randot circles test, were administered to two populations of 3- to 5-year-old children in vision screening settings and to a sample of patients with strabismus and amblyopia. The Frisby test missed (underreferred) cases of binocular dysfunction detected by the RDE and TNO tests, using a 250 seconds of arc (250") (Frisby and RDE) or 240" (TNO) threshold as the pass-fail breakpoint. The TNO underreferred cases at 240" relative to the RDE, but underreferred none if the TNO's breakpoint was lowered to 120". The Randot circles test produced better-indicated stereoacuities than the RDS tests and was found able to reliably grade stereoacuity in patients with stereopsis too poor to be graded by RDS tests.