– The Keystone Red Red Rock instrument allows for the training of binocular vision, eye tracking (saccades) and visual discrimination. – Each slide – which is back-lit through the translucent faceplate – has 15 words or symbols printed on it in black. – The tiles have the same words or symbols printed on them in red. – The student wears red-green glasses that allow viewing of either the tiled words or the words printed on the slide. In this way the student’s brain must use both eyes in order to complete the task. This helps to integrate the right and left brain, resulting in improved visual processing.