Trifocal lenses are part of the multi-focal lens family most commonly used to accommodate presbyopia patients. The trifocal lens offers three fields of vision, which include distance, intermediate and near. The higher the ADD power on a RX prescription, the more notable the intermediate range is for the viewer. As the successor of the bifocal the trifocal consist of an added segment for a near field of vision like the bifocal, but also has a segment directly above to address an intermediate field of view. The trifocal lens may be an alternative to the progressive lens. Unlike the progressive lens the trifocal has a clear peripheral view with most materials, and also offers an intermediate visual range. The trifocal is offered in different segment sizes, which include 7X25, 7X28, 7X35, 8X35 and an executive style lens (also known as an e-style lens). See samples below.
Note that the segment on the e-style lens covers the extent of the lens