Traditionally eyeglasses were made of glass but today they can be comprised of synthetic materials that include polycarbonate, CR-39 and plastic. These synthetic materials are very durable and much lighter than traditional glass lenses.Synthetic eyeglasses can also filter out UV light to protect your eyes, are very durable and can transmit visible light much better the glass eyeglasses. Some of the newest materials for eyeglasses, one being izon, can even correct higher eye aberrations which could be difficult to fix.
Most eyeglasses are used to correct Vision Correction. These eyeglasses achieve this in a way so that when you combine the lenses in your glasses with the lenses in your eyes you can see clearly. Eyeglasses can be used to correct farsightedness, nearsightedness and astigmatism. Most vision problems will require prescription glasses which require and eye exam. However very mild forms of farsightedness can be corrected using over the counter reading glasses.
Eyeglasses can also have several different purposes. There are safety glasses that are used by many different industries to protect the eye from any flying debris or chemicals. Safety glasses are shatter resistant and can have temple shields to protect your eyes from all directions. Safety glasses are required in all laboratories as well as industries that use heavy equipment such as limber, the food industry and many more.Sunglasses is another type of eyeglasses. Sunglasses can be non prescriptive or prescriptive. Sunglasses are used primarily in bright light as they protect the eyes from UV light and can shield your eyes from very bright light. The most recent form of sunglasses are photochromatic. Photochromatic lenses will darken as the amount of light increases so that when you are outside and in full sun they turn into sunglasses but when you are indoors they are clear.
Sunglasses can have many different types of tints. Yellow sunglasses are particularly useful for driving as they improve your depth perception, There are many other types of color tints but they will not benefit your vision at all. Many people chose sunglass tints for aesthetic purposes as they match their hair or eyes.