Glasses are a combination of lenses and frames, which are used to improve vision, protect eyes or for decorative purposes. Glasses can correct a variety of vision problems, including myopia, hyperopia, astigmatism, presbyopia, strabismus or amblyopia.

Glasses consist of lenses and frames. There are 15 kinds of myopia glasses, hyperopia glasses, reading glasses, astigmatism glasses, flat glasses, computer goggles, goggles, night vision goggles, goggles for e-sports games, sunglasses, toy glasses and sunglasses. There are also special glasses for viewing 3D stereoscopic images or virtual real images.

Other types of glasses include goggles, sunglasses, goggles, etc. , providing various protective effects for the eyes. Modern glasses usually have a nose pad in the middle of the lens and a cushion where the left arm and right arm rest on the ear. People who love beauty or are not used to wearing glasses can choose to correct their vision with contact lenses.

Units refer to organs, organizations or departments subordinate to organs and organizations; Refers to the name of the standard quantity for measuring things in mathematics or physics. Generally, there are: meters (m), kilometers (km), cattle (ton) n, pa (ska) pa and other units.

In the traditional sense of Buddhism, units refer to quantitative units such as length, quality and time. And there are special terms such as: moment, moment, snap of fingers, moment and so on. Accurately speaking, a unit is a group of a certain amount of substances defined as "1" to become a unit.

Broadly speaking, unit is a relative concept and an abstract concept, which can form an individual on the coordinate axis of the object coordinate system. The smallest unit of things is zero.