But that doesnât actually tell us what the difference is between the two. In reality, the difference between local and central fire alarms for renters insurance is based on who they alert. A local fire alarm sends a signal, usually a rather obvious noise that alerts residents of the apartment or building in question.
For other uses, see Cornea (disambiguation) . The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. The cornea, with the anterior chamber and lens, refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power.In humans, the refractive power of the cornea is approximately 43 dioptres. While the cornea contributes most of the eye's focusing power, its focus is fixed.The curvature of the lens, on the other hand, can be adjusted to tune the focus depending upon the object's distance.n humans, the refractive power of the cornea is approximately 43 dioptres. While the cornea contributes most of the eye's focusing power, its focus is fixed. The curvature of the lens, on the other hand, can be adjusted to tune the focus depending upon the object's distance.
Its transparency permits light to pass into the eye, through the pupil, lens, and onto the retina at the back of the eye. The three major corneal layers are the outer layer of the cornea or epithelial layer, the middle layer termed the stroma, and finally a single layer of cells called the endothelium. The curvature of the cornea plays an important role in focusing (refracting or bending) light. The normal cornea is smooth, clear, and tough. It helps protect the eye from infection and foreign material.