miriam schapiro art Glasses, also known as eyeglasses or spectacles, are devices consisting of glass or hard plastic lenses mounted in a frame that holds them in front of a person's eyes, typically using a bridge over the nose and arms which rest over the ears. Glasses are typically used for vision correction, such as with reading glasses and glasses used for nearsightedness. Safety glasses provide eye protection against flying debris for construction workers or lab technicians; these glasses may have protection for the sides of the eyes as well as in the lenses. Some types of safety glasses are used to protect against visible and near-visible light or radiation. Glasses are worn for eye protection in some sports, such as squash. Glasses wearers may use a strap to prevent the glasses from falling off during movement or sports. Wearers of glasses that are used only part of the time may have the glasses attached to a cord that goes around their neck, to prevent the loss of the glasses. Carpenters, masons, bricklayers, other workers and also ordinary people that do not have any knowledge on carpentry are adding this compact laser leveler inside their toolkit. This is since Bosch Quigo is not hard to handle without any complications and reliable since it is 100% straight as a result of horizontal and vertical laser reference lines it projects. The range of frequencies readily available for AM transmission comes from 535 to 1705 kilohertz. There is also the Frequency Modulation or FM technique, in which the frequency - instead of the amplitude - of the second signal is regulated based on the carrier wave. For a better understanding look at the comparison image.