Presbyopia is a common, age-related vision condition that makes focusing on close objects difficult. It occurs because the natural lens inside the eye gradually thickens and loses flexibility. This change reduces the lens’s ability to change shape when shifting focus from distant to near objects, a process that usually starts around age 40. This condition can be managed with various corrective solutions, including specialized contact lenses.
Multifocal Contact Lenses
Multifocal contact lenses are a primary option for managing presbyopia, designed with multiple prescription powers in a single lens. This allows for clear vision at various distances—near, intermediate, and far—eliminating the need for reading glasses. These lenses operate on the principle of simultaneous vision, where your eye looks through both distance and near prescriptions at the same time. Your brain learns to select the focus it needs for the object you are looking at.
These lenses are available in two main designs: aspheric and concentric. Aspheric designs feature a gradual shift in power from the center of the lens to the outer edges. Often, the near correction is in the center, and the power changes toward the periphery for distance correction.
Concentric designs use distinct, alternating circular zones of near and distance power, much like a bullseye. The center may be set for distance or near vision, with surrounding rings providing the alternate power. Both designs aim to create a smooth visual transition without the visible lines found in bifocal glasses.
The Monovision Method
An alternative strategy for correcting presbyopia is monovision. This method corrects one eye for clear distance vision and the other for clear near vision, often using standard single-vision contact lenses. The dominant eye is fitted with a lens for distance, while the non-dominant eye receives a lens for close-up tasks.
The success of monovision relies on neural adaptation. The brain learns to process visual information from both eyes and selectively pay attention to the clearer image for the task at hand. When looking far away, the brain favors the distance-corrected eye; when reading, it favors the near-corrected eye.
While many people adapt well, this method can involve visual trade-offs, as depth perception may be slightly reduced. The convenience of being free from reading glasses makes this an effective choice for many individuals. The use of standard lenses can also make it a more accessible option.
The Fitting and Adaptation Process
Successful contact lens wear for presbyopia begins with a thorough fitting by an eye care professional. During this appointment, the practitioner will conduct vision tests and discuss your lifestyle and daily visual demands. This information helps determine whether multifocal lenses or a monovision setup would be more suitable for your specific needs.
Following the initial assessment, you will be given trial lenses to wear for one to two weeks. This trial period is a key part of the process, allowing you to experience the lenses in your real-world environments. Your eye care professional will use your feedback to make any necessary adjustments to the lens power or design to optimize your vision and comfort.
Adjusting to either multifocal or monovision lenses requires a period of adaptation as your brain learns to process visual information in a new way. It is common to experience initial visual disturbances, such as slight blurriness, ghosting, or halos around lights, particularly at night. These symptoms are normal and typically diminish as your brain adapts over several days or weeks.