Trifocal Lenses
Bifocals allow the wearer to read through one area of the lens, and to focus on distant objects through another area of the lens. As the eyes age, a stronger prescription is usually needed to read. As the bifocal power increases, the range of focus becomes more shallow, making it difficult to focus on objects at intermediate distances. Thus, trifocals are necessary for a third prescription for intermediate focusing.
Trifocals, also known as lined trifocals, feature three areas of focusing power, each separated from the other with a vivid line. The three windows allow for focusing on distant objects, intermediately distanced objects, and for up close. The downside of trifocals is dealing with the lines between the different focusing powers. The advantage of this design is that the intermediate and near sections are wider than those in progressive lenses.
Trifocals, also known as lined trifocals, feature three areas of focusing power, each separated from the other with a vivid line. The three windows allow for focusing on distant objects, intermediately distanced objects, and for up close. The downside of trifocals is dealing with the lines between the different focusing powers. The advantage of this design is that the intermediate and near sections are wider than those in progressive lenses.
