When we have blurred vision or irritation in our eyes then we might be having defect in our vision. To correct our vision, we might need to wear glasses. There are two types of vision errors that can come, one is nearsightedness, which means we can only see near objects. The other error can be farsightedness, which means we can see only objects that are far away. We wear glasses for these vision correction. There are lens in the glasses that can adjust the vision defect.

Glasses are generally made of plastic lens and frames that are either made of plastic and metals. Plastic made lens are of low weight and do not put much pressure on the nose bridge. Earlier they were made of glass materials , which used to be heavy and left permanent impression on the nose bridges.

Nowadays, lens are being used instead of the glasses. Lens are the size of the iris of our eyes and can be directly worn over the iris inside the eyes. They are a thin layer of fiber with corrective lens. People wear lens instead of glasses, so that they look younger than wearing glasses. But one has to very careful about wearing and maintaining lens. They can damage the eyes if not properly taken care of.