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.
In the refraction of a ray of light, the angle through which light is refracted depends on wavelength; the angle of refraction is greater for shorter wavelengths than it is for longer ones. Consider white light passing through the slit of a narrow diaphragm and then through a glass prism, as in Figure 3.