The traditional IOLs that have been in use for several decades are called monofocal lens implants because they provide a single focus when you are not wearing glasses. Depending on the lens power selected by the eye surgeon, your eye may see best at one range - far, near or midrange when you are not wearing glasses. Most people who have cataract surgery with a traditional IOL chose to have a lens that provides good distance vision without eyeglasses. If you chose a traditional monofocal lens, you can expect to see well at all distances when the appropriate eyeglasses are worn.

With a monofocal IOL set for distance, you will need to wear reading glasses for close-up vision. If you chose to have a monofocal IOL set for near vision, allowing you to read without eyeglasses, then you will need eyeglasses to see clearly in the distance. Presbyopia is the decreased ability to focus up close, and affects everyone by their mid-40s. It develops when the eye's natural lens loses its flexibility, making focusing up close more difficult.