Presbyopic individuals always move the books and newspapers further away from their eyes, in order to get proper focus. As people age, their eyes gradually lose elasticity and people in their 40s are commonly bothered by presbyopia. Those people always find it difficult to switch focuses between near and distant objects. Currently, various types of eyeglasses and contact lenses can be used to correct presbyopia.
Available in both soft and rigid gas permeable materials, bifocal contact lenses are the most commonly accepted lens type on the market. Acuvue Bifocals is one of the most famous brands of bifocal lenses. Bifocal contact lenses belong to multifocal contacts, which is an overall concept referred to any lens type that has more than one power. While a bifocal lens has only two focal points, a trifocal lens offers three focal points.
Simultaneous vision of bifocal contact lenses requires a wearer to look through both powers at all times, so that the eyes should choose an appropriate power at a specific situation. There are two designs of this type of bifocal lenses: concentric ring design and aspheric design. A rigid gas permeable bifocal lens usually has a distance prescription in the center and a near prescription around it. In contrast, the center-near design is usually applied to soft bifocal lenses. Aspheric bifocal lenses have both powers blended across the lens, similar to progressive lenses.
There are still alternating vision bifocal lenses, with which the pupil alternates between the two powers according to objects in different distances. Also called translating lenses, alternating vision bifocals have a much smaller diameter than other types. In addition, this type of bifocals needs to stay in position all the time.
With the options of both simultaneous vision and alternating vision bifocals, it is necessary to consult an eye doctor before making a decision. A person’s add prescription and pupil size all play a role. For instance, aspheric bifocals are not suitable for people with large pupil.
Presbyopes still have other options for vision correction. Monovision lenses correct one eye for close vision and the other for distance vision with two respective powers. This type can benefit those who have difficulty adapting to bifocals. In most cases, bifocal contact lenses can provide satisfying vision correction.