Manipulation of Light
Optic lenses are substances that allow light to pass through them while manipulating its density or its trajectory. They are typically made from glass or plastic, but can be constructed from any material that is clear enough to allow at least some light to pass through it. The purpose of optics is to either project an image onto a target, to alter the focus of the image in some way or to alter the size of the image.
Light projectors operate by projecting an image onto a desired surface from another location. A common example of this is a schoolroom projector that an instructor uses to display information to everyone in his or her class. By writing or printing the desired projection on a clear sheet of plastic and then placing the sheet over the projector's light table, the image is redirected through optic lenses inside the projector's head and displayed on a screen for everyone to see.
Optics lenses are also used for the magnification of microscopic images. This is done through a series of optic lenses that spread out normally dense light particles, called photons, over a larger area. As the light particles are spread each time they pass through an optic lens, the resulting image becomes larger for the next lens to then magnify. When the final image is projected onto the desired surface, microscopic particles can be viewed as images that are clearly discernible to the naked eye.
The earliest use of optic lenses was for the refocusing of light onto a particular point. More specifically, optic lenses can be fixed into position in front of the wearer's eyes through glasses, and the trajectory of the light passing through the lenses will be altered so that the normally blurry image that the wearer might see becomes more focused and clear. The reason this sometimes becomes necessary is that the ciliary muscles controlling the shape of the human eye's natural lens are sometimes unable to perform their inherent function. Glasses aid the human eye by focusing incoming light enough so that the ciliary muscles don't have to work as hard at the task. The end goal in crafting optic lenses for glasses is to produce a perfectly focused image onto the retina wall in the back of the human eye, which is the image that the brain actually sees.