Keystone Ophthalmic Telebinocular
The Keystone ophthalmic telebinocular was developed in 1934 by E.A.Betts, a reading disability specialist He believed that reading problems resulted from eye problems; so, he devised a testing system. It tested visual acuity, fusion, stereopsis and other functions. It had an 85% failure rate among the students taking it. It was rejected by ophthalmology but was the forerunner of other testing methods still in use today.
