Benjamin Franklin is reputedly the inventor of the first bifocal lenses. He had his optician split his distance and near lenses in half and join them together down the middle. This allowed excellent distance and near vision with one pair of glasses. Of course, times have changed and the manufacture of multifocal lenses has become much more sophisticated. There is still a place however for the original bifocal design. In this case our client is an airline captain and his visual needs are quite demanding. Many pilots do quite well with standard progressive lenses, however my client feels uncomfortable with the slight peripheral blur experienced with them.
Below is a photo of the pair that I made for him. They have his full distance in the top, gauges distance in the middle and the near is for the fine detail of filling out paperwork. All set at the correct heights for easy usage.
There are many instances when patients can be assisted with Franklin split bifocals/trifocals, in particular eye muscle balance issues and problems that arise when the lens power is different in the right and left eye. Really, the use for these lenses is only limited by our imagination.