Maddox Rod

Historical Significance: Maddox devised this test to dissociate the eyes for the measurement of heterophoria in 1890. The glass cylinder is placed in front of one eye and distorts a point light source into a line so that the line cannot be fused with the point source of light. It was later developed to be a larger aperture with multiple grooves (cylinders) know also as the Maddox rod or sometimes as the Maddox groove, although this later development was due to Aiken in 1894.The test is usually administered with a red filter in one eye to enhance the dissociation and modern Maddox rods (grooves) are made with red glass. See books by Maddox Cat No 107. 206, 207, 504. Maddox was an English ophthalmologist (1863 - 1933) who importantly elucidated the nature of binocular fusion and the components of convergence. He invented the Maddox rod and the Maddox wing test, the cheiroscope and the V test for astigmatism. He was ophthalmic surgeon at the Royal Victoria Hospital, Bournemouth, and formerly Assistant Ophthalmic Surgeon in the Royal Infirmary Edinburgh and Syme Surgical Fellow at Edinburgh University. See Cat No 554 for another example.