Why is peripheral vision not bleached by daylight?
Short answer
In photopic lighting, peripheral vision is mediated by cones.  

Background
The rods are indeed saturated at daylight, and even at twilight (source: Nature). However, the cones are active and although their density in the periphery is low, they are still present (Fig. 1). Hence, peripheral vision in photopic lighting conditions is mediated by cones. Because of their low density in the periphery, however, visual acuity is low (Kolb, 2012).


Fig. 1. Rod &amp; cone densities in the retina. (Kolb, 2012)

Reference
- Kolb, Photoreceptors, In: Webvision: The Organization of the Retina and Visual System. Utah University