Foveated rendering

One of the frustrations with this analysis is that we have not been able to exploit that fact that photoreceptor density decreases away from the fovea. We had to keep the pixel density high everywhere because we have no control over which part of the display the user will be look at. If we could track where the eye is looking and have a tiny, movable display that is always positioned in front of the pupil, with zero delay, then much fewer pixels would be needed. This would greatly decrease computational burdens on graphical rendering systems (covered in Chapter 7). Instead of moving a tiny screen, the process can be simulated by keeping the fixed display but focusing the graphical rendering only in the spot where the eye is looking. This is called foveated rendering, which has been shown to work [106], but is currently too costly and there is too much delay and other discrepancies between the eye movements and the display updates. In the near future, it may become an effective approach for the mass market.