Earwigs eat aphids and several other harmful pests as well as hosta leaves. Some gardeners put up with the damage and leave the earwigs in the garden to control other pests. You can control earwigs with traps. Place a piece of crumpled paper under a flowerpot or use a tube of paper or bamboo as a trap.
In optics, refraction is a phenomenon that often occurs when waves travel from a medium with a given refractive index to a medium with another at an oblique angle. At the boundary between the media, the wave's phase velocity is altered, usually causing a change in direction.
Refraction of Light. Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.