Double-ended Handheld Occluder, black and red maddox lens. 

Maddox rods are used in conjunction with prisms measuring lateral and vertical phoria in both near and distant vision. The Maddox rod test can be performed in free space without use of the phoropter. Maddox rod phoria testing is a suitable alternative to the Von Graefe Phoria technique, and is indicated when a patient is unable to see two targets in the Von Graefe test.