RTS: The human eye can see only one point clearly at any moment. The point of clarity is only available in the center of the visual picture.
RTS p147: 2+ types of light receptors in the retina — cones and rods.
- Cones are designed for clarity and color perception in medium or bright light. The great majority of the cones are located in the center of the macula lutea at the fovea centralis. There are only cones exactly in the center of the fovea — no rods. There is a small number of cones extending out from the fovea. Unlike the cones in the fovea, these “peripheral” cones, like the rods, are buried under 8 layers of retinal cells and blood vessels. These peripheral cones do not pick up the degree of clarity and colors that the high density of cones in the fovea do.
- Rods pick up “unclear” movements, grays, and black/white shapes in our peripheral vision. Unlike the cones, they can function in very low levels of light. The rods are located outside the center of the fovea centralis.
Peripheral vision is whatever is outside the exact center of the visual field at any particular instant. The peripheral vision is 20/400 unclear — at best!
Centralization is making the maximum usage of the fovea centralis’ cone density by narrowing one’s visual attention, or interest, to one small, central point of visual interest. The spatial limitation of centralization is compensated by the constant movement of the eyes and the immediate memory of the prior points of interest.
Diffusing = “spaced out” staring, uses mostly peripheral vision
Centralizing = “pointing” like a laser beam
Primary exercise meant to practice and refine the centralization point:
- Centralize on 1 of 2 objects which are separated by a distance
- Switch back and forth between the two objects, centralizing on each one only
- Gradually reduce the distance between the objects until they can each be centralized even while side by side
- Reducing the size of the objects used
- Reducing the distance between the objects
- Increasing the number of objects used
- Varying the patterns objects are placed in
- Keeping the practice objects visually interesting