Bifocal contact lenses have become a popular alternative for many people who have developed presbyopia. They work in a similar manner as bifocal eyeglasses. The main part of the lens is adjusted for distance vision while a smaller area (a narrow band around the lens, within the optical zone) is adjusted for reading vision. After an adjustment period, the eye learns to automatically look through the correct area of the lens depending on whether sharp near vision or sharp distance vision is needed.
The most effective bifocal contact lenses are made of rigid gas permeable plastic. They are most suitable for persons who already wear "hard" lenses who are beginning to need reading glasses. As of this writing, there is no effective bifocal soft lens. Soft lens wearers desiring to discontinue reading glasses are best off trying monovision.